I'm wondering if anyone can help diagnose my problem. The running lights (head & tail lights & license plate) suddenly stopped working one day. I checked the fuse box behind the battery & discovered that the "Tail Lamp" one had blown. I tried disconnecting the tail lights & pulling the bulbs from the turn signals individual to try and single out the source but the new fuses still kept blowing. I'm not sure what the problem is. The little lights at the top of the headlights (4 markers) still light up then go out as I tried new fuses but I don't know how to access those if that's even possible. If it helps the harnesses for the tail lights & headlights (main bulb not turn signal since high & low beams still work) sat out in the rain for a little bit while the car was at a shop but had a few days to dry in Houston heat before anything was plugged in or turned on. When things were plugged in they ran fine for under a week but now it suddenly went out. Any help would be much appreciated.

 

YEAR?, COUPE?,Any MODS ( led brake lights?? After market head lights??)
Any after market sound system ?

 

2003. Touring model coupe. Swapped to 06+ oem tails and head lights but those have been running for over a year with zero issues. There is a pioneer double din head unit. When messing with it last week I blew the radio fuse but that was fixed quickly. Not sure if that would have anything to do with the lights

 

Be a great place to start checking for a short.

 

UNLESS the wiring for the DIM line came into play….. Food for thought...

 

I did check, when I replaced the radio fuse I double checked all wires to make sure nothing else would happen. And what do you mean by the DIM line?

 

There is a line in the multi pin connector for the Stereo, that has 12 volts on it, when you turn the lights on. for a factory unit , it activates the back light.. for a aftermarket unit, you use it for DIM ( or lower the NAV display brightness ) .....

 

Ok I'll pull the stereo out again this weekend and take a look at it. Thanks for the advice! Will update as soon as I finish

 

Find a wiring diagram for that circuit. You need to get a multimeter and isolate the circuit and check for continuity to see if there is a short. If your fuse keeps blowing there is most likely a short in the wires.

 

A good " trick " is to wire a tail light bulb ( series ) with the tabs of a blown fuse....
Plug that ( FUSE LIGHT ) into the circuit that is blown...
So as you apply power , and the short exists.. the bulb will be lit... how bright the light lights is how bad the short is... full bright= dead short....If this was me.. I would start wit the light lit, and unplug bulbs in sections... Left tail , right tail, license plate lamp....
If the light DOESN'T go out.. the short is elsewhere...
Then you need to follow the harness to see if there is a chafe or rub through, causing the short....

 

You guys were right it was the DIM line it was tangled up & shorting out every time the running lights were flicked on. Thanks again for all the help I was able to get it fixed & running normally now

 

Great !!