STRANGE electrical problems

[mazur]

I havn't always had these problems, but have been having them for several months if not more.

1 - First off, if not having run the car for a while, when trying to start it I have trouble. At first the problem was just a real slow cranking. Now, I have a problem that for the first few moments my CEL doesn't light up, I hear a relay begin buzzing along with tach going to 1k rpm, and then suddenly it goes to normal with CEL lighting up.

If I have run the car not long ago it will usually start up normally. This leads me to believe I have parasitic drain, but forgot the method to finding the source.


2 - Before driving off, the lights are very dim and ABS light is on. Not until I hit about 3k rpm does everything get bright and ABS light turns off.

Alternator is fairly new (4 months old). I forget if this problem began when I replaced the alternator, but it's a possibility. Bought the alt. from Autozone...Thinking it might be a fuxored voltage regulator?


3 - Sometimes my check panel on the roof resets when I touch the brake pedal which makes the check light begin blinking. Using turn signal or turning on my headlights usually will cause this to happen as well. I have a V1 radar hardwired into a power source and ground behind the check panel and am starting to wonder if this is causing this.



If anyone has any opinions or suggestions, please help a brother out.

[blueapplesoda]

I have the same exact problem as you, after rebuilding my motor....i put my motor back in and this is what it does. Oh and I know i have a sort of battery drain aswell...but i havent tried to find it yet.

I had to rev it past 5k, then i changed the alternator (albeit with another old one i had laying around from a parts car) and it changed to having to rev it past 4k. yes, all my lights are all dim and whatnot till i pass this level.

Something is causing a fluctuation in the voltage.

My Innovate LM-1 and Megasquirt says the voltage its receiving is around 10.1-10.9v during its warm up period, which i believe is only running off the battery. once i rev it past 4k, it jumps to about 12.0-13.0v and everything seems to operate fine. My lm-1 is hardwired to the constant +- in the engine bay, straight battery.

The biggest problem is it causes my megasquirt to run extremely rich, hot or cold, until i rev it past 4k, so all this black crap builds up inside my exhaust and when i rev a few times it would spit black soot on everything 5 feet behind my car.

[87bimmerguy]

I know this is an old thread, but my car is doing this too. Every time I start the car, all the lights are dim, the fan runs slow, the wipers run *really* slow, until I rev the engine to about 3500, then the lights brighten up and everything runs as it should. Does anybody know why this happens?

[Dresden87]

i know this is an old thread, but my car is doing this too. Every time i start the car, all the lights are dim, the fan runs slow, the wipers run *really* slow, until i rev the engine to about 3500, then the lights brighten up and everything runs as it should. Does anybody know why this happens?

Me too

[87bimmerguy]

Bump?

[87bimmerguy]

Bump on an old thread still have this problem

[87bimmerguy]

I found this helpful information in another thread

I 'm trying to figure out some draining issues as well

I started off with exciter circuit issues, D+ on the alternator was damaged from the cluster to the alternator. It goes from the battery positive to the cluster bulb(charge light) to D+ on the alternator. It kick-starts the alternator or something... Someone else can explain it better. Point is, if that isn't hooked up, the alternator won't start charging the battery(mine would kick on if the motor revved to about 3.5k. If your charge light does NOT come on when you put the ignition into position II(run, no crank), you need to replace the bulb or inspect this exciter circuit.(post 87s do not have this issue, and have a resistor inline with the bulb incase it burns out the battery will still charge). if the light DOES come on, you know your exciter circuit should be functioning correctly. Make sure that the alternator is producing adequate voltage to charge the battery.

If still have issues with the battery not holding charge, 1st off, make sure the battery is good. After that, test for parasitic drain/parasitic draw. Get a ammeter and remove one of the battery poles. With the car off and key out of ignition, doors closed, etc:

measure the amperage across the terminal. It should be less than 50ma. Mine was 200ma, and I figured out that the PO hooked up gauges to non-switched power. Unplugging those gauges dropped me down to 22ma. You can start pulling things in the fuse box while watching the ammeter -- When you see something drop significantly, find out what that fuse is for and inspect devices that are connected to it. Your problem will be there.

Sounds like that's my problem– my batt light has never worked. Problem is, I replaced the bulb with a known good one and it still doesn't work. I have a new alternator. I suspect the problem may be in the instrument cluster itself. Anybody have any ideas?