I have a 88 S4 Vert.. I just got the car about 2 weeks ago and i was looking into changing the radio.. i took the radio out and the the factory harness was bypassed but the previous owner didnt tap or cut the harness at all.. they basically hard wired it in.. i unhooked the radio and installed another aftermarket radio the exact way it was previously and i kept blowing the illumination fuse and the parking lights went out and the power antenna stopped working.. i discounted the radio and the fuse doesnt blow anymore but i still have no parking lights what so ever and the antenna doesnt work either.. im not to worried about the antenna just the parking lights cause i got pulled the other day lol.. anyone have any ideas, thoughts, or prayers for me?!?

 

ive had a similar problem with my fc maybe i can help, i just have a couple of questions. Do your guage cluster lights and dash lights still work?

 

i had and still have the same problem with my 86 fc if a stereo is hooked up my parking lights dash lights and tail lights dont work if a stereo isn't hooked up everything works fine...oh and they did the same thing with my wiring harness in my car also i just came to the conclusion to leave a stereo out of my fc

 

You might have grounded the Red/Black wire which would have caused your problems. You could disconnect the plug to the light switch and first check to see if you have voltage on the White/Green wire in the light switch harness plug. If there is voltage present w/o the key as it should then jumper the voltage to the Red/Black wire in the same plug and the parking lights should turn on. The parking lights, side markers and tail lights all use voltage supplied by the Red/Black wire so if one is out then they are likely all to be out. If they are all indeed are out and the Illumination fuse is properly powering up the White/Green wire w/o key then either the light switch is damaged or the connecting harness is damaged or less likely would be both are okay but the R/B wire farther down the line is fried.

And what fc DonnyB asked is pertinent to your problem. If your gauge and dash lights work then your light switch would appear to be okay such that the problem lies within the wiring harness instead, either at the light switch harness or thereafter.

 

Seems as though your Red/Black wire at the radio unit is connected up wrong as its job is to "illuminate" the radio and not serve as a ground.

 

My gauge cluster still works and my ac/heat panel still work as well.. i had to fix it quick so i took a wire and ran it to the drivers side tail light and ran it to the room fuse and put it on a toggle switch for the time being until i have another chance to get to mess with it... when i hook the switch up and flipped it on all of my parking lights worked again.. but the red/black wire behind the radio the previous owner ran the radio ground into that part of the plug.. i actually unhooked it and ran a new proper ground fo it to the body of the car but the parking lights still didnt work... So the white/green wire behind the light switch should have power all the tiem with the key out? if so i will get a test light and check the voltage and make sure that its getting proper power.

 

donnyb and skkitz.. try running a wire hard wire with a toggle switch for a quick fix on the lighting issue until you can sort it all out proper.

 

Besides the parking lights, which there are two of them in the front, do the sidemarkers (front and back), license plate lights,tail lights, and glove box light work or are they all out as well?

 

Everything went out.. side markers tag lights and glove box.. but i wired into one of the tail lights and i guess since they are all on the same curcuit they all work now.. i have to go in a trace the red/black wire in the radio hole to see if it burnt out anywhere.. im willing to bet that i burnt it down the line cause everythign else is fine