So I've got a 91 RS 305 TBI, and the previous owner installed aftermarket HID headlights, not just bulbs but the kit with the wiring harnesses and the whole nine yards. I had a problem with my headlight pull knob, it would not turn on the headlights. Through playing around with it, I twisted it all the way to the right and it clunked, and immediately the headlights start working. But now with the headlights or parking lights off, if I hit the brakes my turn signals and sidemarkers, passenger and driver side in the front all come on. Turn sinals operate just fine with headlights on and off, parking lights on and off, while not touching the brake, and work fine when touching brake with headlights or parking lights on. They only seems to be affected when headlights or parking lights are off. I'm trying to figure out where to begin chasing this trouble down. Seems to me it would be a ground, and I suspect the headlight pull knob. Any ideas? How hard is it to remove/replace one of those pull knobs? Any help is greatly appreciated.

Sorry forgot to mention... When the turn signals and sidemarkers come on solid as I hit the brakes, I've noticed the needles in the gauges in the dashboard (which are also aftermarket - white face reverse glow) light up as well, and go out when you let up on the brake. Very strange.

UPDATE - So the PO forced the wrong bulb into the driver's side tail/brake light socket. After removing that I no longer have the turn signals and sidemarkers lighting up when I hit the brakes. But my suspected issue with the headlight knob has gotten worse. Now I have no tailights or parking lamps at all... but the turn signals operate properly and everything else seems fine.

Does anyone know if the whole dash have to be pulled to replace the headlight pull knob?

i just changed the dash harness in mine and put a new headlight switch in.... i always wndered the same thing cuz mine was acting up to, but now that i did it i dont c any other way than pulling the dash... i didnt think it was that bad and u cld probly get away with just pulling it back enough to chnge it.

sorry bout my last reply u def can replace the headlite switch without dash removal. i did it and its not bad

Finally got around to fixing the problem. I ended up removing the instrument panel to make room next to the switch so I could get at it, and found the wiring harness melted at one of the contacts going to an orange wire. Figuring this was the problem I got another harness from a junkyard and replaced it. Now everything is working great. Don't know why it melted in the first place, hopefully the ground in the tail light that I already fixed. Maybe it won't happen again.