Driving Light Problem

[dmk]

I successfully installed Hella Optilux F1500 drive lights with an autoswitch on my 04 Roadster a few months ago and everything was working fine with my swith being the TSC. The lights are mounted under the oil coolers. Last week they just stopped working. I checked the following:
1) fuse for the lights
2) fuse tap and fuse it was connected to (#8) - tested with a light also and was getting power.
3) Wiggled all the wires
4) Check connection at the relay in the fuse box

Does anyone have any suggestions on the most common causes for the lights to stop working. I haven't yet checked all of the negatives because I was hoping not to take the tank off, if at all possible. Thanks in advance everyone.

[boxermania]

Dan

It appears hat you have a bit of troubleshooting to do......I don't know your skill level, but one easy way to proceed is:

With the switch on and a 12V ice pick tester trace power all the way to the drive lights.
Check the bulbs with a battery charger.
If the power is present and the bulbs are good, jumper the drive light ground to a solid ground.

Hopefully you'll find where the break is.....it might be with the relay. Hard wire the light contacts at the relay.

Good luck.............

[rdsmith3]

I would first check for a bad ground connection. If that is OK, then trace back with a volt meter as suggested above.

P.S. I assume you checked the bulbs?

[owldaddy]

I'd agree with rdsmith3, sounds like a bad ground. I have my lamps set up the same way, always worked without fault for 4 years, I would add one thing, it could be a bad autoswitch, can you hear the switch "click" when you turn on the lights? If not then it is connected to the switch, which also could be a bad ground, not necessarily a bad switch, but it gives you someplace to start looking.

[dmk]

Thanks, guys for all your help. Owldaddy, I cannot hear a click when I turn on the lights... is there an easy way to check the autoswitch? I'm showing my stupidy of the subject here, but how would you check the autoswitch with a volt meter? Also, I did not check the bulbs - I was just figuring that the chances of both of them burning out at the same time after only a couple of months was quite low.

[Sunbeemer]

My Autoswitch came with an LED on a long wire that will glow red briefly when you first turn on the ignition, and then again when you hold the cancel switch until the Autoswitch turns on the lights, then the LED will turn green. This indicates the Electronic part of the Autoswitch is working correctly, but doesn't confirm operation of the relay that controls power to the light's. That would be done using a voltmeter at the relay's input and output terminals to determine that 12vdc is switched on to the lights by the Autoswitch.

Then there is the grounding of the lights, which is always a good place to start, as was mentioned. Check grounds for the Lights, the Autoswitch, and the relay.