Electrical Issues

[ECTurboDSM]

Ok, my problems have gone through a few stages, so I'll start at the beginning. I was driving to school and my radio would die when I hit the brakes and eventually the car started to die when I stopped. I made it to school but when I went to leave, the car wouldn't turn over anymore. I went and got a new battery but I bought a different group size since they didn't have the one I needed and I needed it right then. It has the same CCAs and reserve capacity but I failed to notice that the terminals were reversed. You can guess what happened, I hooked it up backwards and lots of sparks. I flipped it around and got it home. The battery was still not recharging, so I had the alternator tested and it was bad. I put a new alternator in and still had problems. Things like the automatic seat belts and radio and the beeping when you turn the key weren't happening until the car was started. The radio (Alpine CDA 7892) was still dying when ever I hit the brake pedal. It happened even when I was sitting still in the driveway, and I checked the ground for the radio and it was a good ground. I replaced the 80A alternator fuse, and a good majority of the large fuses in the engine bay and also in the fuse panel in the driver side foot well. I did three consecutive starts tonight and by the fourth, it wouldn't start anymore. I pulled the battery and the alternator and had both tested and they both tested good. The alternator had a slight odor to it, so they replaced it (lifetime warranty, i wasn't going to complain). I just finished putting everything back in and the car started (as it should with a recharged battery) but the alternator light is on now. I am about to blow this car up, so anyone who could possibly save my sanity and the car, we would both appreciate your help. Thanks.

 

[jaredgsx]

sounds like there juice in your system for some reason. I would try a yello top battery

 

[ddavisaf]

Make sure all of your car grounds are good. ie the ground for the transmission, intake manifold, block, etc...
Make sure your battery terminal connectors are in good shape.
Above all else make sure your ECU is good. Pull it out and open it up. You're looking for leaking capacitors. Smell test may or may not work, so I recommend you pull the unit and open it up.

 

[luv2rallye]

...my radio would die when I hit the brakes...

If all the ground points are found good, you may have a short in your stoplight circuit. Do your stoplights dim when you press the brake pedal (engine off)? If so either your battery is not holding a charge or you have a short. For short finding see: http://www.dsmtuners.com/forums/showthread.php?t=179481.

 

[ECTurboDSM]

If all the ground points are found good, you may have a short in your stoplight circuit. Do your stoplights dim when you press the brake pedal (engine off)? If so either your battery is not holding a charge or you have a short. For short finding see: http://www.dsmtuners.com/forums/showthread.php?t=179481.

That's what I was thinking. When I press the brake pedal, the interior lights almost go out and the head lights dim. I'll look into that, thanks.

 

[kscott]

On the battery positive terminal, there should be 3 things/wires.
1. the little hanging fusebox
2. wire going to the starter
3. wire for everything else in the car (incl. alternator).

On the negative terminal, there should be 2 wires.
1. wire going to the starter
2. wire going to the firewall.

The above is correct for my '92; I assume it's probably the same for '90.

When the battery gets changed, it's easy for someone to forget
and leave one of these hanging in midair. This could cause the
battery to gradually be discharged, and/or other strange stuff.

 

[ECTurboDSM]

Well, to add to the list of strange occurances, nothing in the interior works anymore(I have not changed anything from the last time, just went out to move the car). The automatic seat belts don't come back, the radio doesn't work, and the interior lights don't come on. The warning lights in the gauge cluster do work and just like when the first alternator went, the alternator, coolant, and brake lights are on again. All of the cables are attached to the terminal posts.

 

[onecoolkat]

Hey, Im having the Same Problems as listed above, May I inquire as to what solved your problem?

 

[Smitherines]

Same here, car works fine, but nothing in the interior works.

 

[toybreaker]

This is why it's really cool when people post up what solves their problem. You found this thread by searching, and the answer *should* have been here...

Anyway, let's just start over.....

So, there was some kind of a three stooges episode involving jumper cables and/or some advanced automotive slapstick... WTF etc...

Anyway, now there's some electrical problems...

The first thing is a thorough fuse inspection. There's some big ones on the positive battery cable. You can give them a quicky visual easily enough. For some reason, the factory refers to these as fuse link/sub fuse links...but they're really just jumbo fuses...When there is multiple circuits affected, these are usually to blame, so look carefully at the little wire bridge inside. If it's not intact all the way across, it's toast.


There's more in the relay/fuse box at the right front strut tower, and the box at the rear of the engine compartment, left side, also has some smaller fuses/relays. And, of course, there's the fuse panel inside the car by the drivers left foot area.

After you've given the big fuses a quicky visual, it's time to get out a test light (less than 5 buckish at checker) and start testing the smaller fuses electrically. They have built in test points you can probe with the test light tip. Find a good chassis ground for the alligator clip (ground) wire end of your testlight. (pretty much any bare metal will do) Just turn the key on, and touch the testlight tip to the little tab accesible thru the little hole on the end of the fuse. Touch one side of the fuse, and then the other. The bulb will light on a live circuit.

If it lites on one side and not on the other side of the same fuse you just found a popped fuse. (And, very likely your problem )

If it doesn't light on either side, either that circuit isn't energised (turned on by a headlight switch, etc..), or it's lost power upstream.

Run all the fuses in the boxes, and make note of how many aren't operational, and if they share any common power source/fuse link upstream. If you have to, refer to the wiring diagram to see under what conditions that particular fuse is hot.

If there's a few out, go back to the big fuses. Remove the fuse, look at it again, and if you suspect it, try replacing it with a known good fuse. If necessary, you can check it for continuity. Normally, I usually just test the big fuses by substitution, as there isn't an easy way to check them installed. -just please use the correct fuse rating-


While the fuse is out, you can check for power to the fuse base, (with your test light), where it plugs into the harness..one leg should always be hot.

Please note, the alternator fuse bolts into the front box, so it's checked differently. You can access the bolts, and check for power with your testlight. Both sides should be hot all the time. A lot of times a three stooges episode with jumper cables will take this fuse out, If you're still/also having a charging system/lite problem, check out gtm's two minute alternator test,..it's a good way to quickly diagnose charging system problems...For now, just know it should be 12.5ish volts at the battery, engine off, and 13.5ish~14ish running

That's pretty much it unless it's a weird one.

Since you're both having issues involving interior circuits, I'd look at the fuse box by the drivers feet carefully. It's possible a harness got kicked loose or something simple. There's a few harnesses that plug in there, and if one of them gets unplugged, you could get some weirdness.

Occaisonally, the wire that feeds the front fuse box from the battery can become corroded/broken by battery acid inside the insulation. Make sure to check for this if the front box is dead.

Make sure the battery terminals/connections are clean and tight at the battery posts.

Make sure the ground wire from the battery has a good connection down on the bellhousing, and that there's a suitable ground from the battery to the chassis.

Performing these simple steps will give you a firsthand knowledge of your dsm's power distribution, and will allow you to solve this problem, or at least narrow it down so you can ask more specific questions....

please post back what you find, and we'll get to the end of this yet....

 

[titengo]

I had a similar problem with my 93 TSi. When I turned the lights on they weren't that bright and whent I pressed the brake they'll light up normal. Then a lot of fuses started going out and had all sorts of electrical problems. After a lot of searching and fuses burnt the problem was the stop and rear signal lights that it had were a single filament and it uses double filament. After I replaced them the car went back to normal. I don't know maybe it could be something like that

 

[silvercoupe97]

Great post toybreaker!
My interior lights aren't working either and I have a feeling that it has a lot to do with my alternator, whether it's the fuses or regulator because my TT shows below 12volts at idle and nothing more while driving, all the while dwindling.
I've just replaced the alternator and battery and it still has the electrical anomalies, so I guess it's time to recheck the fuses. I won't discount the "new" alternator either since they can be tested as good at the shop, then get damaged enroute to the car.
A lot of the electrical components will act squirrely when starved for power, to include internal lighting, radio, headlights, etc...even as my dash cluster still lights up, nothing else is working as advertised, as I am having this very same issue. The more critical systems will have the power diverted to them, such as the instrument cluster and ECU...that's a good thing, .
Anyway, I'll post back with my findings in hopes to help.