Something electrical is wrong and you do not yet know which part. This page is a triage tool: match your symptom to a subsystem, work through the checks in the right order, and know what a shop will charge just to find the fault.
ModerateLimited driving$122–$1,087 diagnosis through major component replacement typical repair
Quick answer
Electrical faults are frustrating because one failure can produce symptoms in places that look unrelated. The single most useful thing you can do is work out which subsystem is implicated before you touch anything — battery, charging, starting, a specific circuit, or a control module. Use the triage table below to do that. If you are here because the battery keeps going flat, or the car will not crank, those have their own dedicated pages and you should go straight there. And if you are wondering what a shop will charge just to find the fault: RepairPal puts electrical system diagnosis at $122–$179, which is a figure almost nothing else on this topic publishes.
Diagnostic summary
Problem
Car Electrical Problems
Severity
ModerateGet it looked at soon
Can you drive?
Limited driving
We are not going to give this page a single safe-or-not verdict, because "electrical problem" covers everything from a dead radio to an airbag system that will not deploy, and no source supports one blanket call across that range. The triage table below carries a severity rating per symptom instead, which is the only honest way to answer it. What we can say generally is that electrical faults are unusually good at producing surprises — owners have reported to NHTSA cases where a module fault locked them out of the vehicle entirely, or where the engine kept running after the stop button was pressed.
Typical repair
$122–$1,087 diagnosis through major component replacement
Common causes
Dead or weak battery, Faulty alternator, Bad starter motor
Symptoms you might notice
Dim or flickering headlights, especially at idle
Named by both UTI and East Georgia Tire among the classic signs. Lights that dim at idle and brighten when you rev usually point at the charging system rather than the bulbs, because the alternator's output rises with engine speed. If they flicker at a steady speed, look at grounds and connections.
Slow engine crank
UTI lists slow cranking as a primary electrical symptom. It means the starter is not getting the current it needs — which can be the battery, the cables, the terminals, or the starter itself. See car won't start.
A click when you turn the key, but no crank
Also from UTI's list. A single loud click usually means the starter solenoid engaged but the motor did not turn; rapid clicking usually means there is not enough current to hold the solenoid in. They point at different things.
One accessory stops working — the radio, a window, the wipers
UTI notes this pattern. A single function failing suddenly is the classic fuse signature, and it is the cheapest thing on this page to check. If replacing the fuse blows it again immediately, stop replacing fuses and start looking for a short.
Several unrelated things failing at random
UTI describes random and unpredictable failures across systems. On an older car this pointed at wiring and grounds. On a modern car it can equally mean one control module is misbehaving and taking a dozen unrelated functions with it — see the section on modules below.
A burning or hot-plastic smell
Named by LaFlamme's Auto and Allen Turner Chevrolet. Overheating wiring and connectors smell distinctly of hot plastic rather than of oil or rubber. This is the one symptom on this list that justifies stopping rather than scheduling.
The battery dies again shortly after a jump start
Either the battery will no longer hold a charge, the alternator is not replacing what you use, or something is draining it while the car is parked. Those are three different repairs. Car battery keeps dying works through the distinction.
Warning lights appearing on the dash
LaFlamme's lists dash lights among the signs. Which light matters enormously — a battery light is a charging system message, while ABS and airbag lights indicate that a safety system has taken itself offline. Each has its own page.
What causes it
1
Dead or weak battery
Very common
Every single page we examined on this topic leads with the battery, and that consensus is worth something even though nobody publishes actual frequency data. UTI attributes the symptoms — slow crank, dim lights, warning symbols — to age, short trips that never fully recharge it, and temperature extremes. A battery is also the cheapest thing on the list to test, which is why it goes first regardless of whether it is genuinely the most common.
How to spot it
Slow crank, dim lights that brighten as the engine speeds up, and a battery that reads low on a multimeter after sitting overnight.
The fix
Test before replacing. A battery that keeps failing when the battery itself is fine points at the charging system or a drain.
$449–$486 installed, RepairPal national average•DIY friendly
2
Faulty alternator
Very common
UTI names the alternator second and attributes failures to age, faulty diodes and worn belts, with symptoms including the battery light, dim interior lights and a whining noise. The alternator's job is to run the car and recharge the battery once it is started, so an alternator failure presents as a battery problem — which is why so many people replace a perfectly good battery first.
How to spot it
Battery light on while driving, lights that dim as you add electrical load, and a battery that goes flat again within days of replacement.
The fix
Charging system test, then replacement if output is low. Check the belt and tensioner at the same time.
$806–$1,087 installed, RepairPal national average•Shop recommended
3
Bad starter motor
Common
UTI lists a click without a crank, or intermittent starting, as the starter's signature, with wear, oil leaks onto the unit, and faulty wiring as causes. The intermittent case is the frustrating one: a starter with a worn spot on the armature will work perfectly nine times and fail on the tenth.
How to spot it
A click but no crank, or a car that starts fine most of the time and then does nothing at all, often resolved by trying again a few minutes later.
The fix
Confirm voltage is reaching the starter before replacing it. The fault is often in the wiring or relay rather than the motor.
$564–$793 installed, RepairPal national average•Shop recommended
4
Blown fuse
Common
UTI attributes blown fuses to power surges, ageing wiring and overloaded circuits. This is the one cause on the list that an owner can genuinely resolve alone, and it is worth checking early because it costs almost nothing.
How to spot it
One specific function stops working, abruptly and completely, while everything else is fine.
The fix
Look for the broken metal strip inside the plastic body and replace with the same amperage — never a higher one. If it blows again straight away, the fuse was doing its job and something downstream is shorted.
No reliable published range•DIY friendly
5
Wiring faults and short circuits
Common
UTI lists corroded connectors, rodent damage and poor aftermarket installation as causes, producing random failures, flickering and repeat fuse blowing. Rodent damage in particular has become more common as manufacturers moved to soy-based wire insulation.
How to spot it
The same fuse blowing repeatedly, symptoms that change when you go over bumps, or several odd faults appearing at once after a cold spell.
The fix
Tracing a short is skilled work and the cost depends entirely on where the fault turns out to be. RepairPal draws the line plainly: repair beyond fuses, obvious wire damage, dirty connectors and bad relays should be left to a professional.
No reliable published range•Shop recommended
6
Parasitic drain
Common
Something continuing to draw current after the car is switched off and everything has gone to sleep. Only one of the seventeen pages we examined on this topic even names it, which is a remarkable gap given how many people are dealing with a battery that goes flat while parked. Fluke and Optima both publish thresholds — and they disagree on what counts as normal, which is covered in its own section below.
How to spot it
The battery is flat after the car sits for a few days, but the car runs and charges perfectly once started.
The fix
A parasitic draw test with a multimeter, pulling fuses one at a time to find the offending circuit.
No reliable published range•Advanced DIY
7
Corroded grounds and connectors
Common
Named by Chloe's Auto Repair and almost nowhere else, despite being one of the most common real causes of the weird, intermittent, seemingly-unrelated faults that drive people to search this topic. Every circuit needs a return path to the body of the car; a corroded ground strap makes that path resistive, and the symptoms show up wherever that ground is shared.
How to spot it
Odd, intermittent behaviour in multiple systems at once. Lights that dim when a different circuit is switched on. Greenish or white powdery corrosion at terminals.
The fix
Clean and re-torque grounds and battery terminals. This is accessible DIY work and costs almost nothing.
No reliable published range•DIY friendly
8
Control module failure
Occasional
Essentially absent from every page ranking on this topic, and yet it is the cause that best explains modern symptoms. A single failed module can produce faults across many unrelated systems. NHTSA recall campaign 20V771000 is a clean documented example: Honda recalled certain 2018–2020 Accord Sedan and Hybrid and 2019–2020 Insight vehicles for a body control module software error causing "malfunctions of various systems such as the windshield wipers and defroster, rearview camera, exterior lights, audible warning of a stopped vehicle, and power window operation." One fault, six unrelated symptoms.
How to spot it
Multiple unrelated systems misbehaving together, or behaviour that is plainly illogical rather than merely broken.
The fix
Requires factory-level diagnostic equipment. Sometimes a software update, sometimes a module replacement and programming.
No reliable published range•Shop recommended
How to diagnose it
1
Look at the battery terminals before anything else
Open the hood and look for white or blue powdery buildup on the battery posts and cable clamps. Corrosion there adds resistance to every circuit in the car and produces symptoms that look like a dozen different failures. Clean the terminals and clamps with a wire brush and re-tighten. This is free, takes ten minutes, and resolves a genuinely surprising proportion of "electrical problems."
Tools: Wire brush, Spanner
Result: Either the problem goes away, or you have eliminated the single most common trivial cause.
2
Check the fuse for the affected circuit
If one specific function has stopped, this is where to look. Pull the fuse and hold it up to the light — a blown fuse has a visibly broken metal strip inside the plastic. Replace it with the same amperage rating, never a higher one. A higher fuse does not fix anything; it just moves the failure point from a cheap replaceable part to the wiring itself.
Tools: Fuse puller, Replacement fuses, Owner's manual for the fuse map
Result: A restored circuit, or the knowledge that something downstream is drawing too much current.
3
Measure battery voltage with a multimeter
With the engine off and the car having sat for a while, measure across the battery terminals. Optima's guidance is that the key to long battery life is keeping voltage from dropping below 12.4 volts, below which "sulfation begins to diminish both capacity and performance." Note that this is a battery-health threshold rather than a replace-it-now trigger — we have seen a 12.6 volt "replace the battery" rule published elsewhere and we are not repeating it, because it conflates state of charge with battery condition.
Tools: Digital multimeter
Result: A read on whether the battery is holding charge.
4
Test the charging system
Start the engine and measure across the terminals again. Voltage should rise, because the alternator should now be running the car and recharging the battery. If it does not rise, the alternator or its belt is the problem and the battery is a victim rather than a cause. If it rises but the battery still goes flat overnight, move to the next step.
Tools: Digital multimeter
Result: Separates a battery problem from a charging problem.
5
Test for parasitic draw if the battery flattens while parked
This is the test that finds the thing draining your battery overnight. The critical detail almost everyone gets wrong: modules do not power down instantly. Fluke notes they require 10 to 45 minutes to enter sleep mode, and a reading taken before then is meaningless. Full procedure and thresholds are in the section below.
Tools: Digital multimeter with a 10 A range
Result: A current figure and, by pulling fuses one at a time, the specific circuit responsible.
6
Know where to stop
RepairPal draws the line explicitly and we agree with where they draw it: "Electrical repair beyond fuses, obvious wire damage, dirty connectors, and bad relays should be left to a professional." Past that point, diagnosis needs factory diagnostic software and specialty equipment. RepairPal also notes that complex intermittent electrical issues may need referral to a diagnostic specialist, and that testing after repairs is mandatory.
Result: A decision to hand off, made deliberately rather than after buying three parts that did not fix it.
Repair options & cost
Clean battery terminals and grounds
Effectively free and it belongs first on any list. Corrosion on the terminals or a poor ground connection produces symptoms across multiple systems at once, which is exactly the pattern that makes electrical faults feel unfixable.
No reliable published rangeDIY friendly
Fuse and relay replacement
A few dollars. Genuinely within reach for any owner. The one rule that matters: same amperage, and if it blows again, stop and find the short.
No reliable published rangeDIY friendly
Professional electrical system diagnosis
RepairPal puts this at $122–$179, and it is the most useful number on this page because it answers the question everyone actually has: what will it cost just to find out. RepairPal describes the work as testing the entire electrical circuit involved, using "multi-meters, factory diagnostic software, test lights, resistors, external power sources, and many other specialty tools." Their range excludes taxes and fees and does not factor in your location.
RepairPal's national average is $449–$486, of which $60–$88 is labour and $389–$398 is the battery itself. That parts figure is higher than many people expect, and it reflects that modern vehicles increasingly use AGM batteries and that some require the new battery to be registered to the charging system.
$449–$486 installed, RepairPalModerate DIY
Alternator replacement
RepairPal: $806–$1,087, with $195–$286 of that being labour and $611–$801 the part. The part dominates, which is unusual and worth knowing when you compare quotes.
$806–$1,087 installed, RepairPalShop recommended
Starter replacement
RepairPal: $564–$793. Access varies enormously — on some engines the starter is at the front and takes an hour, on others the intake manifold has to come off first.
$564–$793 installed, RepairPalShop recommended
Wiring repair, short circuit tracing, and module replacement
We have no reliable published cost range for any of these and we are not going to estimate. The cost of tracing a short depends entirely on where the fault turns out to be, and a fault that takes twenty minutes to find and one that takes six hours are the same repair on paper. Module replacement additionally depends on whether the part needs programming to the vehicle. The honest advice is to pay for the diagnosis first and get a quote on the actual fault.
No reliable published rangeShop recommended
This range spans a diagnosis fee at the low end and an alternator replacement at the high end, and it is not a typical figure — "electrical problem" is not one repair. The most useful number here is the diagnosis cost of $122–$179, because that is what you commit to before anyone knows what is wrong. Beyond that, some electrical repairs are free (a fuse, a clean terminal) and some have no defensible published range at all (wiring harness repair, short circuit tracing, control module replacement) — we say so rather than inventing one. All figures are RepairPal national averages and exclude taxes and fees, and costs vary by vehicle, location, labour rate and parts.
When to see a mechanic
▸You can smell burning or hot plastic. Overheating wiring is a fire risk and it does not improve by itself.
▸A fuse blows again immediately after you replace it. The fuse is doing exactly what it exists to do. Replacing it repeatedly, or fitting a larger one, moves the failure into the wiring harness.
▸Airbag, ABS or traction control warning lights are on. Those systems have taken themselves offline, and you cannot tell from the driver's seat whether they will work in a collision.
▸Multiple unrelated systems are misbehaving together — that pattern points at a shared ground or a control module, neither of which is a parts-swapping exercise.
▸The fault is intermittent. RepairPal specifically notes that complex intermittent electrical issues may require a diagnostic specialist, and intermittent faults are where DIY parts-swapping wastes the most money.
▸You have replaced the battery and it went flat again. Something else is happening and the next battery will do the same.
▸You are past fuses, obvious wire damage, dirty connectors and bad relays. That is RepairPal's line and it is a sensible one.
Start here: which subsystem is your symptom pointing at?
Every page we found on this topic gives you a list of parts that can fail. None of them tells you which one your symptom implicates, or what order to check things in. That is the gap this table is meant to fill. Find your symptom, note the likely subsystem, and follow the link — the dedicated pages go deeper than a hub page usefully can.
What you are seeing
Likely subsystem
Urgency
Where to go next
Battery flat after the car sits for days, but runs fine once started
Parasitic drain, or a battery no longer holding charge
Every ranking page on this topic lists components that fail. Not one gives a sequence. The order below runs cheapest and most likely first, and each step either resolves the problem or eliminates a branch.
1
Visual inspection of the battery and its connections
White or blue powder on the terminals, loose clamps, a swollen battery case, chafed or rodent-chewed wiring anywhere visible. Free, and it resolves more faults than it has any right to.
2
Fuses for the affected circuit
Only relevant if a specific function has stopped. Same amperage on replacement. If it blows again, stop — you have a short, not a fuse problem.
3
Battery voltage, engine off
Establishes whether the battery is holding charge. Optima's threshold for long-term battery health is keeping voltage above 12.4 volts.
4
Battery voltage, engine running
Should be higher than the engine-off reading, because the alternator is now doing the work. If it is not, you have a charging fault and the battery is a casualty.
5
Parasitic draw test
Only if the battery goes flat while parked. Requires letting the modules fall asleep first — 10 to 45 minutes per Fluke — or the reading is worthless.
6
Ground and connector inspection
Clean and re-torque the main engine and body ground straps. This is the step that fixes the faults which make no logical sense.
7
Hand off
Past this point you need factory diagnostic software and equipment most owners do not have. Paying $122–$179 for a diagnosis is cheaper than buying two wrong parts.
Why modern cars break the 'one symptom, one part' rule
Almost every article you will find about car electrical problems describes an electrical system that stopped existing decades ago — a battery, an alternator, a starter, some fuses and a loom of wires. That is not what is under your hood.
A modern vehicle "can easily have 70+ ECUs" — electronic control units, each a small computer responsible for some part of the car. They communicate over a shared network called CAN bus rather than being individually wired to each other. CSS Electronics explains the reason plainly: "Traditional point-to-point wiring systems would require dedicated wires between each related node, making the system costly and inflexible." Moving to a shared bus can reduce a wiring harness weight by as much as 20 kg.
Two practical consequences for you
1One failure can produce many unrelated symptoms. NHTSA recall 20V771000 is the clean example: a body control module software error in certain 2018–2020 Honda Accord and 2019–2020 Insight vehicles caused "malfunctions of various systems such as the windshield wipers and defroster, rearview camera, exterior lights, audible warning of a stopped vehicle, and power window operation." One software fault. Six unrelated things broken. If you tried to diagnose that by symptom, you would replace six parts and fix nothing.
2Nothing switches off instantly. Modules stay awake after you lock the car and take 10 to 45 minutes to enter sleep mode, according to Fluke. This is why a parasitic draw reading taken immediately is meaningless, and it is also why a modern car legitimately draws more current while parked than an older one did.
Testing for a parasitic drain
If your battery goes flat while the car sits but the car runs perfectly once started, something is drawing current with the ignition off. Only one of the seventeen pages we examined on this topic even names this, which is a striking omission.
The thresholds — and where the sources disagree
Fluke
Optima
Normal / acceptable
Under 50 mA is normal
25 mA is acceptable
Indicates a problem
Over 100 mA is suspect
Over 100 mA indicates an issue that needs addressing
Published parasitic draw thresholds
They agree on the ceiling and disagree on normal, so we are publishing both rather than picking one. Optima adds useful context: an 85 mA draw "is not all that uncommon on newer vehicles" thanks to memory seats, GPS and satellite radio — and their worked example is that an 85 mA draw will fully discharge a 50 Ah battery from full charge in just over three weeks. That is the mechanism behind a car that will not start after a holiday.
The procedure
1
Shut everything down
Engine off, all accessories off, doors closed, interior lights off. Anything still drawing current will show up in your reading and hide the fault you are looking for.
2
Set the meter up correctly
Multimeter to DC amps, black lead in COM, red lead in the 10 A jack to begin with. Fluke is emphatic that you confirm the leads are in the correct ports before connecting anything.
3
Insert the meter into the circuit
Disconnect the negative battery cable. Connect the red lead to the battery post and the black lead to the cable you removed, so the current now flows through the meter.
4
Wait for the modules to sleep
10 to 45 minutes. This is the step people skip and it is the step that makes the reading mean anything.
5
Read, then pull fuses one at a time
Fluke: "One by one, remove fuses from the vehicle's fuse panels. When the current drops significantly, you've found the problem circuit."
6
Investigate that circuit
Inspect the wiring, relays, switches or modules on the circuit you identified. The fuse only tells you which branch — not which component.
Grounds and connectors: the cause nobody writes about
Exactly one of the pages we examined mentions corroded grounds and connectors. It deserves better, because it is the single best explanation for the symptom pattern that makes electrical faults feel supernatural: several unrelated things going wrong at once, intermittently, in a way that seems to depend on the weather.
Here is why. Every electrical circuit in the car needs a return path, and that path is the metal body of the vehicle itself, connected back to the battery through a handful of ground straps. When one of those straps corrodes, its resistance rises. Every circuit sharing that ground now behaves oddly — and because current will take any path it can find, a circuit with a bad ground may start returning through some other circuit's ground instead. That is how switching on the rear defroster ends up dimming a tail light.
What to look for: greenish or white powdery deposits at terminals, ground straps that look corroded or have been painted over, connectors that are loose or have been disturbed by previous work.
Where to look: battery terminals and clamps first, then the main engine-to-body ground strap, then the body-to-chassis grounds. Most vehicles have several.
What to do: clean to bright metal, reassemble and torque properly. This is genuinely accessible DIY and costs the price of a wire brush.
Why it is worth doing early: it is free, it is quick, and a bad ground can mimic almost any other electrical fault — which means diagnosing anything else while a ground is corroded wastes your time.
What a shop actually charges to find an electrical fault
This is the question people most want answered on this topic and almost nobody publishes a figure for it. RepairPal puts electrical system diagnosis at $122–$179.
What you are paying for is worth understanding, because it explains why the figure is what it is. RepairPal describes the work as "testing the entire electrical circuit involved" using "multi-meters, factory diagnostic software, test lights, resistors, external power sources, and many other specialty tools," and notes that testing after repairs is mandatory. That is a labour charge for skilled time with expensive equipment, not a fee for plugging in a code reader.
Repair
RepairPal national average
Breakdown
Electrical system diagnosis
$122–$179
Not broken out
Battery replacement
$449–$486
Labour $60–$88, parts $389–$398
Starter replacement
$564–$793
Not broken out
Alternator replacement
$806–$1,087
Labour $195–$286, parts $611–$801
Wiring harness repair
No reliable published range
Depends entirely on fault location
Short circuit tracing
No reliable published range
Billed as diagnostic time
Control module replacement
No reliable published range
Varies by module and programming needs
Published costs for common electrical repairs
RepairPal's figures exclude taxes and fees and do not account for your location. Costs vary by vehicle, location, labour rate and parts, and an electrical diagnosis in particular is a time charge — so a shop familiar with your specific model may genuinely be cheaper because they will find it faster.
▸How much does it cost to diagnose an electrical problem in a car?
RepairPal's national average for electrical system diagnosis is $122–$179, and this is the number worth knowing before you book anything, because it is what you commit to before anybody knows what is actually wrong. RepairPal describes the work as testing the entire circuit involved using multimeters, factory diagnostic software, test lights, resistors and external power sources, and notes that testing after the repair is mandatory. Their range excludes taxes and fees and does not factor in your location. It is a charge for skilled time, which is why a shop that knows your specific model can be cheaper — they will find it faster.
▸What are the most common car electrical problems?
The pages we surveyed converge on the same order — battery, then alternator, then starter, then fuses, then wiring faults — and it is worth being clear that this is consensus among writers rather than measured frequency, because nobody publishes real failure-rate data. UTI's list is representative: a dead or weak battery from age, short trips or temperature extremes; a faulty alternator from age, failed diodes or a worn belt; a bad starter; blown fuses from surges or overloaded circuits; and wiring faults from corrosion, rodent damage or poor installation. Two causes are badly under-covered everywhere and belong on the list: parasitic drain and corroded grounds.
▸Can I drive with an electrical problem?
It depends entirely on which one, and we are not going to give a blanket answer because no honest source supports one. A dead radio and an illuminated airbag light are both electrical problems. Use the triage table on this page, which carries severity per symptom. Three cases are clear-cut though: a burning or hot-plastic smell means stop; a battery warning light means the car is running on battery alone and will eventually stop wherever it happens to be; and an airbag or ABS light means a safety system has taken itself offline and you cannot tell from the driver's seat whether it will work when needed.
▸Why do several unrelated things stop working at the same time?
Two likely explanations, and both are under-covered. The first is a shared ground: every circuit returns through the body of the car via a handful of ground straps, and when one corrodes, everything sharing it behaves oddly at once. The second is a control module. A modern car can easily have more than seventy electronic control units on a shared network, and one failing module takes unrelated functions with it. NHTSA recall 20V771000 documents exactly this — a Honda body control module software error causing malfunctions of the wipers, defroster, rearview camera, exterior lights and power windows simultaneously. Diagnosing that symptom by symptom would mean replacing six parts and fixing nothing.
▸What is a normal parasitic draw?
The two best sources disagree, so here are both. Fluke says under 50 milliamps is normal and over 100 milliamps is suspect. Optima suggests 25 milliamps is acceptable and says anything exceeding 100 milliamps indicates an electrical issue that needs addressing. They agree on the ceiling of 100 mA and differ on what counts as normal, which we think is more useful to know than a single number would be. Optima adds that an 85 mA draw "is not all that uncommon on newer vehicles" with memory seats, GPS and satellite radio — and that such a draw will fully discharge a 50 Ah battery in just over three weeks. Critically, take the reading only after the modules have gone to sleep, which Fluke says takes 10 to 45 minutes.
▸When should I stop trying to fix it myself?
RepairPal draws the line clearly and we think it is drawn in the right place: "Electrical repair beyond fuses, obvious wire damage, dirty connectors, and bad relays should be left to a professional." In practice that means cleaning terminals and grounds, checking and replacing fuses at the correct amperage, and basic voltage measurement are reasonable owner tasks. Tracing a short, diagnosing an intermittent fault, or anything involving a control module is not — RepairPal specifically notes that complex intermittent issues may require a diagnostic specialist. The economic argument reinforces it: a $122–$179 diagnosis costs less than two wrong parts.
▸Why does my new battery keep dying?
Because the battery probably was not the problem. Three things can flatten a good battery: the alternator is not recharging it while you drive, something is drawing current while the car is parked, or the connections are too corroded to pass the current in either direction. Test the charging system first — measure across the battery with the engine off, then again with it running, and the second reading should be higher. If charging is fine, test for a parasitic draw. Car battery keeps dying works through the whole sequence, and it is the page you want if this is your specific pattern.
▸Can a bad ground really cause this many problems?
Yes, and it is the most under-reported cause on the topic — exactly one of the seventeen pages we examined even mentions it. Every circuit needs a return path to the battery through the car's metal body, and when a ground strap corrodes its resistance rises. Every circuit sharing that ground then misbehaves, and current starts finding alternative return paths through other circuits, which produces symptoms with no logical connection to each other. It is also the cheapest thing on this page to rule out: clean the battery terminals and the main engine and body ground straps to bright metal, re-torque them, and see what is left. Diagnosing anything else while a ground is corroded is wasted effort.