Help! Serious Electrical Problems!, The weirdest thing I've ever seen... Options

[Coomer]

I'm so confused and scared right now...I can't figure out for the life of me what's going on with my car.

It started with me trying to start it, and only the fans turning on. I checked the fuses and none were blown, so I checked the switched wire at the starter, and it was giving me no voltage.

I then unplugged the battery and went inside to take a break. When I came back out and plugged the battery back in, I noticed that the trunk light didn't turn on. I looked at the dash and the door open light wasn't on either. I tried turning on the parking lights and they didn't turn on. I tried the horn and it didn't work. Basically, nothing on the car works.

This is where it gets confusing. I've got a fuse 6" from the battery, and it's in good shape. Figuring I'd popped some other fuse, I checked all of them in the dash and under the hood, and they were all good.

I pulled the main 50 amp fuse under the hood and tested voltage on the hot side. Voltage started at around 10 volts and over a couple seconds rose to 12.4 volts and held there.

I then tried the same thing for the horn fuse under the hood, and it started at about 8 volts before rising to 12.4 and staying there.

At this point I disconnected the negative cable and came inside. Someone suggested testing voltage between the terminals and the clamps with the headlights on to test for a bad battery connection, but this yielded no voltage. At the battery terminals, I'm getting 12.4 volts. At the battery's fuse and a bolt in my trunk, I'm also getting 12.4 volts.

At this point, I'm so confused. I've never seen anything this weird in my life. Anyone have any ideas?

[Batman722]

Don't be scared, it'll be OK. It sounds like you have to have a poor connection somewhere or something is not making contact. Probably with a wire going from the battery or to the ignition.

what were you doing exactly before this happen ? have you installed any electrical stuff recently ?

[Coomer]

I took out my alarm recently and was working on re-installing it. The car's electrical system seemed to be working, but I hadn't tried starting since my engine was held in by one mount prior to tonight.

[Silvan]

The voltages you measure could indicate that the battery is gone.
example: you measure 12volts, as soon as you start to draw current, the voltage collapses, giving you false readings. Take a big bulb and connect it directly to the battery then measure again. If the voltage drops too much the battery is gone.

[bufferdan]

Test main power source going to the alternator! You can use a wire and jump from battery + to the alternator +. See if stuff works then. When I had this problem, my car actually shut off while i was driving down the street. Come to find out that one of the main power wires that ran to the alternator broke loose at the battery.

[sapperk]

I had that problem on a smaller scale. It turned out my alternator was bad, and my battery was dieing. It was that simple. Try hooking it up to a good battery and see what happens. Then check you main battery cables.

[prez]

i had a similar problem and every few days my battery would go dead... i would charge it fully with a portable charger i have and it would be fine for a few weeks, then i parked it for like 20 minutes and the battery was completely drained, i had weird things with electrical stuff not working... its simply a bad connection, one or more of the connections are in need of cleaning... and its not neccessarily a problem you find AT the battery, you might have to take it in to a good autobody place where the can lift it and clean all the connections... i had to after i thought i fixed the problem (i had a bad battery as well) luckily i have 2 cousins who each own a autobody shop, one does body work, collision repair and painting, one does mechanical, electrical stuff

[slipgun]

Prez, I have a simmilar problem... it drains if I leave it for 1 week. where do you live?

[Coomer]

My battery is fine. I took it out and had it tested today. Anyone have any ideas?

[Snarfer]

What is the voltage drop from the hot side of 50A fuse and the chasis while the fuse is in? I would also check the resistance between the +,- connectors to the battery while they are disconnected. Try to turn everything off on the car, ie disconnect the clock, radio, ecu (i'm not sure on the ignition light timeer) and keep all of the doors closed.

This post has been edited by Snarfer: Apr 13, 2005 - 6:40 PM

[bufferdan]

Like i said..test for voltage going to the alternator.

[Coomer]

Like i said..test for voltage going to the alternator.
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I'll try it when I get a chance to go work on the car.

[946thGenGT]

If it were me I would be backtracking through all the electrical work I've recently done on the car to see if something is crossed or grounded somewhere. I'm sure that was the first thing you tried but it just seems logical that since you're doing work on the alarm that it's related to your problem. Well, good luck.

[Coomer]

If it were me I would be backtracking through all the electrical work I've recently done on the car to see if something is crossed or grounded somewhere.  I'm sure that was the first thing you tried but it just seems logical that since you're doing work on the alarm that it's related to your problem.  Well, good luck.
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I checked all of that stuff already. In fact, the alarm isn't even in the car at the moment. Only a few wires are ran for the alarm setup, and they're all taped off and stuff.

[946thGenGT]

If it were me I would be backtracking through all the electrical work I've recently done on the car to see if something is crossed or grounded somewhere.  I'm sure that was the first thing you tried but it just seems logical that since you're doing work on the alarm that it's related to your problem.  Well, good luck.
[right][snapback]270954[/snapback][/right]

I checked all of that stuff already. In fact, the alarm isn't even in the car at the moment. Only a few wires are ran for the alarm setup, and they're all taped off and stuff.
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Well, this might sound stupid, but have you tried putting the alarm back in? Lol. I'd probably be trying anything and everything if I were in your position.

[bufferdan]

IF you are loosing ALL power then it IS a MAIN POWER WIRE! There are only a couple big white MAIN power wires that run into the fuse box... but check voltage to the alternator...if the alternator is not getting anything then NOTHING WILL.

[von125]

I`m with Bufferdan on this. If your getting low voltage output check out the alternator and it`s connections.

[Coomer]

The alternator is getting +4 volts when the car is off(It can only be off at the moment.) Is this normal? Or should it be +12 volts?

Edit: Today I also added an additional ground wire to the tranny, an additional ground to the battery, and a brand new Optima Red Top. Still the same problems.

[BlackCelicaGT94]

my dad says


"theres a wire that comes off the positive battery terminal that is the main wire that powers up all the instruments, lights etc. and theres usually its either a fused link or a connector leading to a fuse and if theres trouble everywhere its either in that connector or that fused link. im not totally sure. im not aware of the post 90s but i had that problem with teh Supra. but it sounds like u got no juice go anywhere"


"also just as a precaution...hook everything up, turn the key on and check ur voltage at the starter. because theres usually a heavy cable running to the starter check and see if uve got 12 volts there. if u dont then its a pretty good test that either ur battery has got a short underload or its that other connector and fused link are gone"

those are the simple things. on the supra it wouldnt run and couple of points on the ECU. and i had to change ECUs but i still had lights and stuff

This post has been edited by BlackCelicaGT94: Apr 15, 2005 - 12:49 AM

[Coomer]

Bump. Anyone got an answer for my alternator question?