hi. i did some searching and didn't find anything that seemed to help. My headlights work, low beams high beams (it's a 9003 bulb for hi/low ) and once in awhile the pass. or driver side will go out, or the pass will dim, but only on the low beams. if i go up to the light and and hit it with my fist or sometimes the vibes from the clunk of popping the hood will make them come back on....... i've checked the connections, the bulbs look good, any ideas? thanks

Sounds like a loose connector somewhere.

the first place i'd check would be the pigtail connector that actually plugs into the headlight. sometimes on older cars the plastic that holds the conductive connectors together has warped, broken, or melted out of shape, making the connection fail somewhat unreliably. sometimes the metal corrodes as well.


if it's not the bulbs, connectors, or pigtail plugs, you more than likely have a problem in the relay or wiring system. it's time to troubleshoot- just start going through the lighting system- at first with the battery disconnected!- making sure everything looks right. if you can't see anything, you can try swapping components(bulbs, relays) from one side to the other- if the problem switches, you've more than likely found the culprit.

if you can't see anything wrong and can't reproduce the problem, you may need to get out a multimeter and - with proper safety attention and education - test the wires to see where there's current potential and where there's not.


of course, if all of this fails or is somehow not a possibility- take it to a dealer. they will figure out what to do, and whatever they charge is worth it when it comes down to seeing things that you may hit at night.

i'm putting my money on either a wire connector that's loose or a bulb.

thanks, i'll look into that.......hopefully it's not the detective stuff, i could do it but......then i'd have to :) i replaced one bulb (pass) maybe i could go to the junkyard and pick up a couple pigtails and switch them......might work too. I;m not as familiar with relays though....thanks

I'd post this in a new thread, but being new, I cant yet.

I'm having a similar issue, but here's the details - My drivers side headlight went out along with the drivers side brake light (the one that activates only when you brake, not the always on one). The problem is only present on low-beams.

When I remove the fuse thats in the upper right hand corner in the panel under the hood both headlights come on, but they are both very dim.

What does this mean?

aguacate- please let us know what year and model your car is. the wiring is very different for various years.

also, what is the fuse for that changes the problem?

aguacate- please let us know what year and model your car is. the wiring is very different for various years.

also, what is the fuse for that changes the problem?

Sorry, it's a '94 subaru impreza wagon. I honestly don't know what the fuse is for - I don't have the manual and the fuse box under the hood doesn't describe what each one is for. The fuse in question is 15A.

I checked all the fuses under the hood and under the steering wheel, and they're all good.

In that fuse box there are two other types of components - one is a black cube (I assume they are relays?) and the other is a colored cube with clear sections. What are these and can I simply yank them out to test them with my multimeter?

It sounds like you have a lose connection or wire somewhere. I'd get a voltmeter(they're under $20 at radioshack if you don't have one) and test the line that goes to your headlight at various points to see where it stops working. Also, next time it stops working, open the hood and shake some of the wires that connect to the headlight to see if it turns on. That might give you a better idea of where the lose connection is.

I just swapped the pass. and driver side lights, and the driver side lights up now. Apparently it is the light itself. I don't know how it would still dimly light up when I popped that fuse out, but being that I couldn't see any visible damage to the filament, I'm guessing it had to do with being just barely broken. But still, it doesn't make sense to me.

Also strange is that when I tested the resistance on the bad bulb I got infinity all the way around even though the high beams work.

I wish I knew what that fuse went to. Anyone know where a fuse box diagram for my car is on the interwebs?