Hi, I have a 99 mustang GT. I recently installed HID lights with the ballast, and have the Halo headlights.
The lights have worked for about 4 months while the car was parked in my driveway. I was adjusting the lights a few days ago and one of the lights went out. I tested the brokenheadlight, and ballast on the working side and everything was fine, no problems with the light or ballast. I then tested the voltage coming out of the headlight plug and didnt get any voltage. Both high beams and signal lights are working, but no low beams on drivers side. I hooked up a jumper from the passenger headlight low beam wire to the drivers side low beam wire. When I did this and turned on the lights both stoped working. I tested the passenger side low beam at the headlight plug and now i have no power on that side either.

I have the Hanes manual and the wiring diagram in the book is not the same as my car. If anyone knows where I can find a wiring diagram, or help me with a possible solution to this problem it would be greatly appreciated. Thanks

 

I hardwired both ballasts from the battery with a fused line to a switch i put inside the car, then wired my lights to the low beam wire at the headlight plug...everything is working now, but I have an extra switch to use my low beams. I am still looking for a wiring diagram for an american 99 GT

 

have you looked at the fuses? Look at them again and look at ALL of them(both under the dash and by the battery). I am willing to bet you saw some sparks somewhere during your installation?

When I suspect a fuse I check EVERY FREGGIN one!!! circuits are often linked and looped through one another and you will be suprised how the door chime fuse is blown but your headlights don't work.

 

Okay, thanks, I will check them all tonight. I orginally checked the fuses in the car, but I only checked the ones for the headlight. I will let you know what I find.

 

it really is funny what you will find in the fuses, i'm pretty sure you will find one bad.

And now honestly, did you make any sparks ANYTIME during the installation or troubleshooting?

 

Fuses are all ok. What threw me away from the fuses was that highbeams still worked on both lights, but low beam only one, and turn signals worked.

 

if the fuses are good then the only other way to go is to trace the wire that is dead, it must be disconnected somewhere... Sometimes pins in hrns's can get pushed out or even off to the side where it will not make contact. Check your hrns's...