Help Electrical Gurus

[toadleyb]

I am having a very strange problem with my headlights. With the car running and the ebrake off the headlights flicker on and off. As soon as I set the ebrake they shut off completely. I dug into the dash yesterday to see if maybe there was something obvious but could find nothing. I unhooked the headlight switch and pulled the instrument cluster and it still did the same thing. As a temp fix I turned the switch for the ebrake light so that it is always in the on position, now my lights don't flicker but my ebrake light is always on. I am not crazy about this fix as I would really like to find the cause instead of just a band aid.

As a side note I tried to start the car with the instrument cluster unhooked and it would not run. Is it supposed to do this?

Thanks for the help

 

[n0v8or]

What model year is your car? Convertible or coupe?

By "flicker", do you mean similar to a flourescent lamp starting up, or do they stay on and off for several seconds each?

Was there any work done on the car just before you first noticed this problem?

 

[Red2000GT]

Check the e-brake switch. I'll bet you'll find it corroded or dirty. If the lights stay out when the e-brake is on then i'd say the switch is seeing the brake come on and off,causing the lights to flicker.

 

[toadleyb]

2000 GT Coupe. They flicker on and off rapidly almost like the lights on a cop car. My first thought was the kid that owned it before me installed some sort of flasher but I am sure I would have noticed it before this summer. I have had the car about a year and a half. The dealership did look at the clutch for me this summer but I honestly don't remember if it was before or after I noticed the headlight problem.

The car had some wiring issues shortly after I bought it. Evidently the previous owner had some neon lights under it which the dealership stripped off before I bought it. Shortly after I bought it it died completely and the dealership fixed it saying there was a ground somewhere that they did not tighten up when they were prepping it for me to buy.

 

[n0v8or]

If someone has modified the wiring, then I suppose almost anything is possible. For now, let's assume that's not the case, since your headlights did work OK at one time.

Whan you say you completely removed the headlight switch, yet still had flicker, do you mean the headlights still had the problem even with the switch disconnected?

If yes, my first guess would be a defective DRL (daytime running lamps) module, because it is supposed to turn off when the park (emergency) brake is applied. DRL modules were installed in vehicles sold in Canada, and perhaps certain US states as well. With the engine running, headlight switch off, and park brake not applied, the DRL module is supposed to pulse the headlights about 100 times a second. This is faster than humans can perceive as flicker (theatre motion picture projectors flash ~50 images per second on the screen, and US televisions flash 60 video frames per second). your DRL module may be the cause. The headllights should work fine without it.

Another possibility is your car did not come with DRLs, but some clever person used the DRL module connector to tap into the wiring for aftermarket accessories (like neon bulbs).

I doubt if you have a ground problem in the headlamp circuit, because the right and left side use separate ground points, and you did not say that only one side was flickering.

 

[toadleyb]

I can't remember right now how I know but I do believe the car is from Canada. That would explain a lot. I didn't think any of these cars came with DRL's. Can I remove the module if this is the case? If so any idea where it would be located?

Thanks again for the help

 

[n0v8or]

I have the 2001 service manual. Hopefully, 2000 is identical. It describes the DRL module location as "forward of left front fender, below horn". The wire colors to the module connector are as follows:
pink-orange stripe
blue - black stripe (2 this color)
red - black stripe
green - black stripe
black

 

[toadleyb]

Thanks for the help! I will check it out this weekend. I hope this is the problem, I wasn't crazy about driving around with a short somewhere!

I remember how I knew the car was Canadian. The owner's manual is in French!

Todd

 

[ultrashock2112]

I can't remember right now how I know but I do believe the car is from Canada. That would explain a lot. I didn't think any of these cars came with DRL's. Can I remove the module if this is the case? If so any idea where it would be located?

Thanks again for the help

Yeah all cars made for the Canadian market in the last 15 or so years have to have DRL. It's probably because of all the BAD drivers we have here or something. The way it works in my 2000 GT is as soon as the parking brake is off, the DRLs come on. The problem you are having could be the switch that is triggered when the parking brake handle is down. Although I don't know for sure, I'd imagine it is somewhere around the handle itself...