Car is a 96z a4. My passenger side low beam headlight keeps going out, it prolly goes out about once a month an is always the same one.when I bought the car the headlight was out, but the guy bought a brAnd new one for me. Wut do you think is causing this? I've tried looking at them. An I noticed that the aftermarket fog lights were into factory wiring to use factory switch, I complety un hooked the fogs an still no change, the same headlight went out 2 weeks later. Any help would be great! Thanks Colby

 

When you say it goes out, do you mean it just stops working for a bit and then comes back on? Or is it blowing every so often, and needs to be replaced? Also, have you checked the wiring for the headlights as well? It sounds like possibly a bad connection, corrosion, something like that, perhaps.

 

Yes sorry. Everytime it went out I would have to replace the headlight. I recently did a head light swap an I put the round head light in, an no longer then 2 weeks the bulb went out, so I finally wired my headlight to another switch for now so I can drive my car at night. An I forgot to tell yal, that everytime the passanger headlight went out the fog light would go out on that side or not work at all.

 

If you don't want to read all this, go to the bold at the bottom.
This is probably being caused by a high amp. draw. In other words your system is pulling more amps. then the light is rated for. For instance, if you had a 55W bulb and the system is pulling (using) 60 watts your bulb/s will burn out much faster then normal. Is the pass. side bulb brighter then the drivers side?
The most common cause for this is corrosion at the connectors or ground, or bad loose connectors. Less common is a partially broken wire. Say if you have 12 strands in you head light wire and 7 of them are broken, this can cause a higher amp draw on that wire.
However in your case I'll bet it's the fog lamps. Your head light system is designed for a specific load all the wire fuses etc. are rated for just the requirement of it's unique system. You NEVER tap into an existing wire harness to run additional equipment. I.e. you don't use your head light wires to run your fog lights. Your fog lights should be powered directly from the Bat. or a hot Bat. terminal, fused, then though a relay. The realy should be power from a separate fog light switch.
My quess is the fog light installer either damaged the low beam wires or has cause some kind of unwanted draw on them from the installation of the fog lights.

So, bottom line, completely separtate the fog light wires from the head lights. Do not use the head light harness to power your fogs.
Check the connections for corrosion, and good contact, especially the ground. Then check the wires for damage, (partially broken wires).

 

i never noticed if the pass. headlight was brighter than the drivers. i thought it was the fog lights too. i already unhooked the fog light from the car an removed them. that head light blew two more times after thats where im stuck.

 

Broken wires can be especially hard to find. If the fog light installer used any of those clip-on type connectors (the ones that slice though the insulation to make contact with the core wire) that can be a suspect area. You may have to cut out that section and replace it. I would try and find a guy that does automotive electrical and have him look at the system. Even one of those auto alarm and audio installers would be a good bet.

 

I think I mistaking yal. The foglights that were on the car when I bought it, was wired up to the factory wires for the fog lights,not the headlights. So you can use the factory switch next to the headlight switch. My car has a alarm on it, an my ? Is how many wires come of the driving/ turn signals. Cause the guy before me cut an spliced some wires to the drivin light to flash when you lock an unlock the car. Could that be causing my headlight to keep going out.

 

Any another advise?