About the main electric systems of the car. Consider a different tag for radios and other such systems.

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9
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3answers
20k views

Battery drains by itself when vehicle is parked (parasitic draw)

A 1998 Jeep Grand Cherokee has gone through 3 batteries in the last 3 months. While they have all been replaced by warranties, it'd be nice to get the problem solved permanently. I've tested the ...
9
votes
2answers
13k views

What is BCM(Body Control Module) in a car?

I own a Fiat Grande Punto. Recently I was told by the authorized auto workshop that the BCM in my car has failed and needs to be fixed. So i have two questions regarding that - What is a BCM and ...
9
votes
4answers
3k views

2000 Jetta runs rough, shutters on cold start only on wet days.

This is an issue I've had off and on for, embarrassingly, at least a year: On misty or wet mornings, everything starts out fine but, a few minutes into the drive (like clockwork. I even know the ...
8
votes
4answers
3k views

How to assess battery charge level and alternator performance?

What diagnostics can be done to to assess battery charge level? I'm interested both in one-off tests like can be done in car service and also continuous monitoring during normal use. Car panels ...
7
votes
2answers
472 views

My mazda milenia wont rev past 2500 rpm

So I just recently bought a 2000 Mazda Milenia s Millennium edition,and on my first day out with it, I experienced a very unusual problem. After about 20 minutes of driving the car wouldn't rev past ...
7
votes
1answer
116 views

Shutting off fans at highway speeds

On my vehicle (92 Civic) and most others I've seen, the condenser fan comes on whenever the A/C clutch is engaged. This seems like a waste of electricity (and thus fuel) when cruising at 60-75 mph, ...
7
votes
3answers
2k views

Does idle RPM increase when there is heavy load on the electrical system?

I am thinking about installing a 500w halogen (HDX brand) on the roll bar in my jeep as the dome light because often I work in the back when it is dark or when I would like more light. The 500w light ...
7
votes
1answer
217 views

Finding And Fixing A Short

Make: Chevy Model: Cavalier Year: 1993 (old I know) Symptoms Turn signal no longer works. The lights do not come on, and there is no "ticking" sound. New Fuse for signal blows as soon as the car ...
6
votes
4answers
2k views

Why does my car scream on cold start?

My 1988 Subaru XT6 2.7L engine screams at me on a cold start then it will stop and then do it again when I take it out of park, but then it stops. Also, my car is losing antifreeze. Any ideas why?
6
votes
3answers
378 views

How stable is voltage in a 12V car outlet?

I want to use a Mini-ITX PC board in a car. I plan to use the 12V "cigar" outlet or take the 12V elsewhere, but from the same 12V source that is dedicated to be used for user devices within a car's ...
6
votes
3answers
6k views

What are the tradeoffs for positive vs. negative ground?

I just got a classic Ford 8N tractor running again. Someone trying to be helpful flipped the battery around, connecting negative to ground. This made the engine crank backwards! So I had spark, ...
6
votes
1answer
2k views

Why would my electrical systems cut out when I brake?

So I told this little story to the dealership service department, and they were baffled. Never heard of anything like it in ten years, said they'd have to examine it very closely. Here's what ...
6
votes
2answers
350 views

How to detect a failing car alternator..?

Is there some way we can predict that the car alternator is about to fail in order to avoid a discharged battery situation on the road.. Although it will slow the sound of horn and will dim the ...
6
votes
2answers
532 views

Bmw E46: strange problems with automatically closing windows and broken light warning

I have had a couple of strange problems and I can't really make sense of it. When I parked the car, I locked the doors as always with the windows closed (I am absolutely sure about this; it was ...
5
votes
4answers
12k views

Car won't start or stay running after a jump

I have a 2004 Kia Spectra 1.8, I have replaced the spark plugs, the alternator, and my battery is only about two months old. The car will start after a jump but it has to sit for about 10 minutes ...
5
votes
3answers
1k views

How to amplify car speakers without stereo?

I have a 1980 VW Dasher with its original speakers but no radio. It has an unusual (erroneous?) electrical configuration where most accessories (e.g. lights, cabin fan, etc) still run even with the ...
5
votes
2answers
708 views

Have tow ball but not electricity for a trailer

I have a Toyota Camry 2004. When I just bought it, I have noticed that it has a tow ball. I didn't really intend to use it but now it could really help me to move few things around with a trailer I ...
5
votes
2answers
4k views

How do you remove or even get to the car battery on a 2012 Honda Odyssey?

Summary How do you get to the battery on a 2012 Honda Odyssey, given that it is blocked by some type of intake tube**? **Edit: this used to say exhaust but I changed it to intake tube, given ...
5
votes
3answers
560 views

How do I diagnose opened door indicator problem on a Honda Civic 1.8Vti Aerodeck

The opened door light indicator flashes at random rate when I drive. This also randomly triggers the alarm system that I had to disconnect. I have removed every door switches. No differences. ...
5
votes
2answers
2k views

Can an engine stop from a bad battery?

The car is a 2005 Toyota Corolla CE. Its engine is the 1ZZ-FE, a 1.8L straight four that runs on gas, not diesel. The alternator is stock, and tests out just fine on the multimeter in both voltage ...
5
votes
3answers
3k views

2007 Nissan Armada power window fuse location

According to the fuse block diagram, there is not a dedicated fuse for the power windows. Anyone know if the power windows are on another fuse? Front drivers side window will not go down and switch ...
5
votes
3answers
460 views

2007 BMW Z4 won't start when my phone is plugged into the cigarette lighter plug

Sometimes when my cell phone is on charge in my 2007 BMW Z4 before I start it, nothing happens when I turn the key. The car is acting like it would if I did not have the clutch pushed in - the key ...
5
votes
1answer
2k views

What current is “normal” for constant battery drain (not parasitic)

I'm having some problems with battery going dead sometimes, and I noticed that there are some small sparks after disconnecting the battery for a few seconds and then reconnecting again. It is not big ...
5
votes
1answer
184 views

Should I disconnect the battery when working on my instrument cluster

I am going to be changing a few bulbs on my Opel Astra's instrument cluster. Part of the process involves disconnecting the entire cluster from the wiring harness and obviously replacing it when done. ...
5
votes
2answers
896 views

Why are my wires melting together?

I'm currently neck deep in an eletrical shortage issue with my BMW 316i. I found the wires that are blowing my fuses, it's bad. Like at least 5ft of 8 or more wires fused together behind my dashboard ...
5
votes
3answers
384 views

93 Nissan Sentra SE-R, replaced alternator voltage still low

My car died while I was driving it, but I can put the battery on a charger (or from another car, with jumper cables) and get it running albeit for a short period of time. I put a multimeter on the ...
5
votes
2answers
3k views

Manual horn switch

what are the pitfalls or things to look out for when manually wiring a switch from the battery to the horn? Some background: I just moved to texas where they require vehicle inspections. My horn ...
5
votes
2answers
1k views

Daytime running light failure — one side only

I have a 1991 Miata. It's a Canadian vehicle, and so is equipped with daytime running lights. Recently, I've noticed that the passenger side light is not working as a DRL. The driver's side light ...
5
votes
2answers
740 views

Chronic ignition problems with 1996 Suburban, replacing distributor cap makes it go away

I'm trying to diagnose an ongoing ignition problem with a 1996 Chevy Suburban. Sometimes it won't start, and the previous owner said this happens regularly, and every time the problem occurred, ...
5
votes
3answers
111 views

Can an O2 sensor cause faulty spark plugs on driver side only when the spark plugs were just changed?

I took my truck (2006 chevy silverado 5.3l v8) to chevrolet dealership due to the fact that it kept sputtering then dying. The check engine light was on the whole 9 yards. The fuel pump has been ...
5
votes
1answer
175 views

GPS dashboard mount replacement?

When I bought my car, they were doing a promo and shipping a Garmin GPS with it. Thing is, the GPS came with a nice mount, fixed to the dashboard. This was great, because it meant no wires going ...
4
votes
4answers
5k views

What is the best overall ODB2 scan tool?

There are a number of different ODB2 scan tools out there, some PC based, some standalone units, some more for tuning and some more for diagnosing problems. What are the different features that these ...
4
votes
2answers
556 views

Upgrade to HID lights in a Jeep Wrangler

I would like to upgrade to HID lights in my 2008 Jeep Wrangler. The stock lights aren't bright at all. My question is, since this would be an aftermarket upgrade, what am I looking at here? Is it ...
4
votes
2answers
986 views

12v Acc/Switched vs 12v Always On

I am currently designing a part that should always be on when the key is turned to On/Acc, and only sometimes on when the key is set to Off, or removed. My car is a 99 Camry, but I have a good ...
4
votes
2answers
3k views

Can cold weather cause TPMS sensors to malfunction?

I just bought a new 2011 Honda Fit and while driving it home from the dealer, I noticed that a little light on the dashboard was on that said "TPMS". When I got home, I consulted the owner's manual ...
4
votes
1answer
47 views

Wires Coming Out Of Center Console

I bought a 2011 Ram 1500 about 6 months ago. I removed the rubber liner for a small compartment in my center console. When I tried putting it back I realized it would not go down all the way and found ...
4
votes
3answers
503 views

Low beam headlights don't work, High beam headlights do

The vehicle is a 2003 Chevrolet Trailblazer. The low beams aren't working. High beams are. The fuse is perfectly fine (tested and swapped out). The bulbs are fine too. A mechanic told me it could be ...
4
votes
1answer
4k views

How should the lights for a trailer be hooked up?

I have a tent trailer and the lights don't work right. It has a 4 wire connector to my car but one of the wires on the trailer connector was worn out and probably not working. So I got a new 4 prong ...
4
votes
2answers
2k views

Possible short in reverse lights on 2003 Nissan Frontier Pickup Truck

When I engage reverse on the manual transmission of my 2003 Nissan Frontier pickup truck, the reverse lights tend to sporadically turn on and off. I'm trying to figure out what path to take to ...
4
votes
1answer
886 views

How can I diagnose gradual electric power loss in a VW Golf Mk5?

I'm experiencing loss of electrical power to my Mk5 Golf. It seems to happen mostly when the car hasn't been run for two or three days. We changed the battery a few months ago. More recently, there ...
4
votes
4answers
563 views

High Beam Indicator Problem

I have a situation where I'm doing wiring for the dashboard of a vehicle. For whatever reason, the turn signal/headlight switch on this vehicle outputs a 6 volt signal on the high beam wire when the ...
4
votes
2answers
172 views

Audi A6 : brighter reversing lights?

On my 2007 A6 the reversing lights are very feeble, enough to make it quite difficult to reverse in my own driveway in the dark. I understand that I can't simply use higher-wattage bulbs or LED ...
4
votes
2answers
3k views

How can I elegantly secure a USB charging cable to the dashboard?

In extension of this Q about the power outlet I have a related question about how to secure the USB charging cable that runs from the power plug in the cigarette lighter socket to the corner of the ...
4
votes
2answers
138 views

Intermittent stall at idle

I have a 98 Saturn sw2 with a recent problem. Two times now it has stalled while idling and when it doesn't stall it floats near 500 rpms (Usually 750 - 950). The first time, it would start and just ...
4
votes
2answers
2k views

Aux Audio Input for 2006 Honda Accord

I'd like to add an auxiliary audio input to my 2006 Honda Accord LX-SE: What parts do I need to purchase? Can someone with a rudimentary understanding of electronics perform the installation? What's ...
4
votes
1answer
827 views

How to troubleshoot a fan that won't work unless it's on it's on the highest setting?

My car fan won't work unless it's on 4 (full power). I have 4 options of power for the fan 1 - 4 but nothing happens on options 1 - 3. I have taken the panel off and cleaned all the contacts for the ...
4
votes
1answer
587 views

Tail light is intermittently out on Dodge Caravan

I have a 2004 Dodge Grand Caravan. A couple of days ago, the right turn signal started flashing rapidly when turned on to indicate a burned out bulb. I checked and found the right tail light was ...
4
votes
2answers
1k views

What is the correct/factory wiring for a Suburban 1998 battery/alternator?

I have included a picture showing what I have now on this Suburban. Note that there is wiring not shown in the picture which is a second electrical connection to the positive side of the battery ...
4
votes
1answer
79 views

My drivers side window no longer closes with one press of the button 1

I share a similar plight with the guy before only difference is it's with an 04 Forester STi. I held the passenger front window switch up for a little too long next thing I know my driver side window ...
4
votes
1answer
222 views

What's the reason for a battery light coming on and becoming brighter as the engine revs higher?

The vehicle is a 1993 LandRover Discovery 3.5 V8. Today when I hopped in to drive home the battery light came on when I started up, and remained on. It gets brighter as the engine revs and just ...