.. I have upgraded 9004 headlight harness from APC and I'm running 80/100W APC superwhites.. yesturday my right headlight went really dim while the other stayed bright.

Things i think i ruled out:
-bad ground.. i cleaned the ground wire and the metal plate it is attached to of rust and stuff... I had them go dim because of a bad ground before, so that was the 1st place i looked.. before i could just jiggle the wire and they'd get back to normal, now it's definately not the ground..
-poor connection.. i checked the battery terminal the wires are connected to.. everything is secure and tight.
-bad bulb... I swapped in 2 different bulbs, my stock ones and another set of hyper whites.. both of them shine with the same dimness.

I'm thinking it could be the connections inside the socket where the bulb is placed in.. The bulb still shines but i think it might just shine with 1 filament or both, but really poorly. My highbeams are just as dim when i turn them on. Any other ideas on where i should look for the problem?

thanks

 

umm sorry to be of no help, but I have had the same problem for almost a year probably. it's my driver side light.. and its dim. I have tried many different sets of lets i have, and have changed harnesses too - checked my ground , no such luck.

I hope someone knows!

 

have you checked if they're aimed correctly? If one is aimed too high, it will be dim.

 

Voltmeter is your best friend. If you can measure the voltages on both the + and ground side indivually, you can figure out whihc circuit is a problem. If they all check out to be equal, then it's a bulb problem.

 

I had the same problem when I fryed my harnesses (stock) with higher wattage bulbs. Anyways, I put new ones in and had this problem, simply took it to this local shop and had my wiring wrong. I would start with that, and that is probobaly the cause, wires crossed etc.

 

the wires could not have been crossed because it was fine for a long time, i did not mess with them at all, then one headlight just went dim. Like I said, it can't be the bulb either. I put in different bulbs and all of them work dim on that side. I swapped that bulb into the other side, it works fine there.
I checked the ground again, i cleaned the connector plug, battery terminal + checked the fuse. everything is fine... wtf. I know what side it is but where is the problem? Maybe the relays went bad? How do I check those?

Help before i go and waste 30$ for another set of wires..

 

When your lights are on, is yoru hi-beam light in your dash slightly on, not bright but somewhat dim?

 

YES!

 

let me go outside and check right now.. although it's daytime, hard to see anything..

hlh0501... you've driven around like this for a YEAR? damn dude.. I drove for 3 days and I feel embarassed showing my self with one headlight really dim and the other nice and bright......
I think it could be the harness socket burned on one side, although it's good, the black ground wire is a little melted down around the socket. This sucks totally..

 

haha, well I have a get-around for it... I put in upgraded harnesses, and some bulbs (not like "hid bulbs" or any of that crap...), and when I run them on bright, they are both normal brightness, and clear not yellow or blue..

buuuut I have no brights now because my brights are always on.. plus that little blue light is on on my dash which bothers me.

 

well i'm running mine with the upgraded 9004 harness as well. It is supposed to take the higher wattage of the bulbs. wtf. I do not have the dash light on, my high beams suck just like the low beams on that headlight.

 

Yea I am telling you, the wires are crossed somewhere...before i thought I was 100% sure that everything was fine, and the guy switched the wires around and worked fine...try it over and I bet it will work

 

I don't understand how that can be possible if i had the upgraded wire harness in there for over 4 months now and never had a problem and never even removed it or rearranged anything. If they were switched around wrong then i should have had the problem from the beginning, but it was all good.
What wires did he switch around exactly? I'll try it for the hell of it because i don't know what else to turn to.

 

Is it possible 2 of the wires are touching anywhere?

 

FIXED!

I took apart the plug with the 3 wires that is connected to the headlight bulb. I figured it had to be the ground wire from previous experiences. When I grounded it on the engine block it got a bit brighter, so there was a reaction.. When I took apart the plug, the black ground wire was all corroded and had melted pieces of plastic on it.. the small metal pin it is attached to, which contacts the headlight bulb was bent and not touching the bulb right.. just soldered it back and shortened the wire, grounded it on another bolt and it works great now Also installed Polarg 1157 bulbs with the **** filed down, + 194 Polarg sidemarker bulbs looks great now and matches perfectly

 

I was wondering if any one could help me.
Im running with an APC wire harness and 100/80 watt bulbs.
Last night when I got into my car i realized that my
driver side headlight was out.
But the highbeam works.
This is not the first time this has happened.
I had a pair Nokyas for almost a year and the
same driver side headlight did this.
Ive had my new bulbs(JCWhitney) for almost 4 months.
Can anyone think of what the problem might be?
Thanks

 

bump

 

i have the same upgrade apc harness and it's working fine. i hope mines don't melt. what kind and watt bulbs are you guys running?