Weird electrical problem.

nutzforporsche · 11-17-2003, 01:10 PM

Hi all,

I have a really strange thing happening. I replaced all my old turn, stop, etc bulbs on my car. The car runs great, but when I turn on the head light switch, the lights pop up, but my volt guage pegs to zero. None of the lights dim or nothing. I turn off the lights and it returns to like 13-14 volts charging. Everything works ok,..what gives. Any ideas?

Thanks!

SGB · SGB's Garage

There is definitely a short in the light circuit- prob at tail light bulbs you replaced. Although it is difficult (and I never let that stop me from making a mistake), they will go in "wrong" and still lock into place. I betcha one of the bulbs is allowing a direct connection to the chassis, but still lighting the bulb too. I don't think you wanna use the lights till you figure it out. A lot of juice is goin through one of those wires, and it will get hot and melt things, y'know.

SGB · SGB's Garage

Reread your post "...pegs to zero" -zero? hmmmm.... I may be wacky w/ my answer then. Are the lights bright? Do they stay constant (more or less) through the rev range? Those are my armchair mechanic indicators for voltage regulator. (ie: yeah, too bright,and yeah, brighter with revs would make me suspect a regulator) Is the gauge responsive to turn signals (mine hops 3 volts on each "per-plink")? If it isn't, maybe a bad guage or ground. These guys talk about replacing fuse 5 (I think) all the time for crazy sh..t, too.

philinjax · 11-17-2003, 02:28 PM

Steve,
If you lost your voltage reading (I am assuming you have a center console), you would also have lost your oil temp readiing.
I think you may have installed one of your new dual filiment (1157) lamps in the wrong way. You can check this by turning on your parking lights only and then checking to see if one of them, front or rear, seems unusually bright. If this is the case, then that lamp is incorrectly installed and may be the reason for the zero volts with lights on.

Good luck,
Phil

Jim Smolka · 11-17-2003, 02:28 PM

It could be that the ground for the gage is not correct; thereby allowing 12VDC on both sides of the gage. The other possibility could be the loss of 12VDC supplying voltage. Please measure gage voltages before and after.

nutzforporsche · 11-17-2003, 04:41 PM

Eureka!
You might have all touched on something! I put the center console in a while back when I was in process of rebuilding the car.
The other funny thing is that the oil temp has never worked. I tested the sensor and it is good. The lights in all the guages work and the clock keeps great time
.
However.....I wouldn't put noth'in past me when I'm tired and just want to get it overwith sort of thing. I always end up going back and redoing the job twice.

I'm also thinking that I may have put in one of the bulbs bassackwards. They don't look too bright, but it wouldn't hurt to look again. I didn't see them getting any brighter if I gave it some gas.

I'm willing to bet against me that I also have the wires to the oil temp guage missed aligned. Just like a baby gorilla, what I don't tear up.... I sh_t on it......

I'll keep you fellas posted and Thank You for the Help!!!!!!!

Quote:

Originally posted by philinjax
Steve,
If you lost your voltage reading (I am assuming you have a center console), you would also have lost your oil temp readiing.
I think you may have installed one of your new dual filiment (1157) lamps in the wrong way. You can check this by turning on your parking lights only and then checking to see if one of them, front or rear, seems unusually bright. If this is the case, then that lamp is incorrectly installed and may be the reason for the zero volts with lights on.

Good luck,
Phil

nutzforporsche · 11-25-2003, 06:05 AM

Problem solved! First I wanted to Thank all of you with your input and guidance. I decided to look at all of the suggestions. I turned on the parking lights. Went to the back of the car and they were all normal. Went to the front of the car and the turn signal lamp on the passenger side was exceptionally bright. I took the puppy out and swapped it out with a new bulb, double checking the fit. I turned back on the parking lamps all was good. I then turned on the main headlamps and the guage for voltage stayed at 13 volts!
WooHoo problem fixed. It is funny how one little thing makes such a impact!

Many Thanks for all the help!!!!!!!!!!!