Hey all, I'm sure that this has come up a few times but I have yet to run across a thread. I have an 85 2M4 and it has been sitting for a while, I just recently installed all new light bulbs for the tail lights and side markers. The turn signals and brake lights work perfectly but the tail lights and side marker lights do not come on when the headlight switch is on. I looked first at the fuse panel and found that the 20 amp CTSY fuse had a 5 amp fuse in it but was not blown so I put a 20 amp fuse in just to be safe still nothing. Im not sure if it matters but the right side headlight is removed and the left headlight is burned out. Thanks for the help in advance!

Bad connection in one of the bulbs? Check out the Ogre's Cave for something called, "sneak path". Due to the way in which our beloved cars are wired from the factory, this sneak path causes all kinds of wonky things to happen with some electrical components.

http://home.comcast.net/~fierocave/sneakpath.htm

Check your grounds?

GL finding the problem can be a PITA. I would start by checking the connections in the bulb sockets. This was the problem I had in the past. One faulty bulb connection appeared as a much broader problem in my case.

Front, Rear, or Both?
Maybe grounds. Is very common.
Tail fuse and HL switch covers external lights.
Turn and brake lights use Turn B/U and Stop Haz fuses.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Both the front and rear side markers, the license plate lighs as well as the tail lights do not work when the headlights are turned on. The bulbs are all new and the front side markers work when the turn signals are on. I also found two wires hanging near the fuse panel with connectors on each, one is pink and the other is orange with a black stripe, not sure if these have anything to do with this issue but I just thought I would throw that out there as well. Thanks for the help by the way, Im new to the Fiero world and it seems like you guys are a great group.

quote Originally posted by yellowsnow85: Both the front and rear side markers, the license plate lighs as well as the tail lights do not work when the headlights are turned on. The bulbs are all new and the front side markers work when the turn signals are on. I also found two wires hanging near the fuse panel with connectors on each, one is pink and the other is orange with a black stripe, not sure if these have anything to do with this issue but I just thought I would throw that out there as well. Thanks for the help by the way, Im new to the Fiero world and it seems like you guys are a great group.

But the front and rear side markers, license plate lights and tail lights DO work with the headlights off?

Check your headlight grounds? If I remember correctly there is one ground on each headlight. Raise the headlights up, either manually or electrically, and disconnect them so they stay up. You could try the old trick of pushing the HL switch just right so the HL's go up but do not come on. Kinda tricky but it can be done. Then check each HL well for their respective grounds. Clean them up if need be.

IDK but if the lights all work fine till you turn your headlights on I would suspect a sneak path.

Also in my case, even with brand new bulbs, I still had a bad connection in a bulb socket cause all kinds of wonky problems.

Sorry I missed the fact that these were your very first PFF posts! Welcome to the madness! Welcome to PFF. If you ever need a good laugh head over to OT. If you need parts head over to the Mall. Don't neglect the "search" function here on PFF, it can be a great savior!.

GL with the lights and car. BTW we really love pics around here and would love to see your new Fiero!
HAGD!
Andrew