Nicholbry

I own a 1990 S4, originally a Canadian car [don't know if it matters for my question or not].

The daytime running lamps [inner lights that also serve as the fog lamps when the headlights are on dim and the fog switch is turned on] no longer work. I recently replaced these bulbs because one seemed dimmer than the other. Turns out, the light fixture was simply not aligned properly up/down. Both bulbs were changed with standard Sylvania H3-55w bulbs, which is what was in it before. The lamps worked fine for about an hour before they went out. I put a couple more bulbs in thinking that perhaps something was wrong with that batch, but no change.

Upon further inspection, #6 position 15amp fuse (foglights) was blown. I replaced it, but it continues to blow (tried 2x more). I have a relay in position # III of my car (again 1990 S4) that is a light purple color. The chart says it is designated for the driving lamps. Next to it is a silver relay with a purple dot that is designated for the fog lights. One of the prongs of relay #III [driving light relay] appears to be discolored a bit [bluish/purple]....like metal looks when it overheats sometimes. No brown/burnt/black color though. The wires in the lamp area seem to be OK with no obvious signs of burning. The outside bulbs of the lamp (the ones that come on when the headlights are on bright) work fine. The headlights all work OK in both bright and dim modes.

Has anyone had a similar problem. I spoke with someone knowledgeable about 928s, but he doubted the relay to be the problem. Any help would be appreciated.

Mrmerlin

since the lights worked fine before you fixed them,
then you need to go figure out how your grounding the power wire.
my guess is that you have one of the power wires mis routed and its shortiing out when you refit the light housing,
look carefully you should be able to spot the offending wire, try the lights with them taken apart see if the fuse blows,
dont over fuse the CE panel either as this could spell a fried harness

Nicholbry

I'll give that a try. I don't know if it matters or not, but they lamps worked for about 30min - 1hr after I replaced the bulbs. Additionally, the bulbs I replaced simply plugs in one way...with only one wire. So, I can't imagine fouling that up as I didn't have to re-route anything. I simply pulled the single wire bulb out from the connecting wire spade and replaced it with the new one. Nonetheless, I shall take your advice about disconnecting the bulbs and see if that eliminates the fuse blowing.

Thanks Merlin...you always seem to try and help me.

Mrmerlin

usually if it took 30 mins or so for the fuse to blow the wire has gotten hot enough to have its insulation get damaged , i am sure you will find a wire thats touching , also look and see if one of the power wires may have to be routed a certain way to stay away from heated surfaces.
Goodluck with your search,
BTW your welcome for the assistance

Nicholbry

Will do Merlin. Thanks again. I'll report back.

Nicholbry

OK, I've put this job off long enough. Time to get to business as I tend to other matters with the car.

Does anyone know how and where the wires travel beyond the fog/driving lights, specifically? I expect to have to trace the wires back to the offending location. Do they travel within the fender and will they be visible to inspect/repair/replace if the fender liner is removed? Or, do they travel through the engine compartment?

Any recommendations on how to best approach this project? The wires/connections that are visible when the lamp is removed appears to be good there. So, I'm expecting to have to "go fishing". I'm thinking I might as well replace the better portion of the wiring to the fog/driving lamps while I'm at it.

Thanks,
Nicholas

Alan

In the fenders (remove the front splash shields) - these foglights have a 2 part plug-in connector (fixed to the fender inside wall) - you can unmate these and see if the fuse still blows - if not then the fault is in the pigtails to the lamps - if yes its before that on the car side wiring.

I'd also just do this test with all the bulbs removed and see if the fuse still blows. You can remove the DRL relay - and though the fogs won't come on with the ignition - they will still come on with headlights and the switch. From your description - do your DRL's even work (on whenever the car is running....).

Alan

Nicholbry

Thanks Alan for responding and directing me where the wires run.

Being that my car originated in Canada; the running lights normally come on when the car is cranked. There's nothing going on now, however (driving lights or fog lights both left & right side of the car).

Thanks again.
Nicholas