OK, first off I have a 91 RS 3.1 with 157000 miles.

Yesterday the taillights and dash lights fuse blew. I replaced the fuse and it immediately blows when I turn on the lights. Headlights, blinkers, brake lights, etc still work fine.

Here is what I have done so far:

I have removed and inspected (visually) the rear brake light assemblies. I have also removed the dash cluster (I needed to replace a couple of bulbs anyway). I have also unplugged the buzzer (the annoying beep that reminds you to turn off the lights when the car is turned off).

With both of these unplugged (the dash cluster removed and the rear lights unplugged around the rear 'cubbie' area) the fuse still blows. The wires going into the headlight switch appear fine (again just a visual inspection). So here is my thinking. The short is somewhere between the fuse box and either where either the rear brake lights are unplugged or the guage cluster is unplugged. I.E. if the lights switch was bad...it would be throwing the headlight fuse too right?

Is this correct thinking?

Are there any relays in between these points? Anyone have a similar experience? Ive stopped working for the day due to daylight coming to an end and its getting too cold, however Id like to try to solve this prior to Mon.

 

after a little more searching, here is more info. the parking lights dont even come on.

Again headlights work, however tail lights, parking lights, side markers dont.

Im starting to lean toward the headlight switch.

Any ideas?

 

Check all the bulbs and wires for a short to ground. If that reveals nothing you're going to need a schematic to find out what else is on that circuit and see if it is causing the problem.

 

took all the bulbs out and replaced the headlight switch. still blowing the fuse. I did a visual on all the 'pinch points' and connections that i could find. Anyone know what else runs off this fuse?

 

With the lights and car off, do a continuity test to ground on all the wires in the light circuit. The only one that should show continuity will be the fat black one, which is the actual ground. All the other wires should not be touching ground, and if you show continuity on them, that's your shorted wire.

It would probably be easiest to test them at the headlight switch.

Matt

 

ill try that tommorrow.

Now that Ive put the bulbs back in the car (ive got to drive to work in the morning). the right front parking light wont blink when using the blinker, however it does blink when the hazard are turned on.

weirdness.

Any possibility that this is associated with the rest of the stuff?

 

I have run into this problem with THREE T/A's

My gta had a pinched wire at the tailights.

My Friends t/a we still havent figured it out yet.

My friends other t/a we never figured it out either. We sold that one.

The blinker/parking light bulb, has two filaments in them, In essence two lights in one.. so if one of the filaments burns out then it will only work when the good filament is in use.

 

Jutt26, just curious, where are you re-placing this fuse.... and what size are you replacing it with?

BTW, do you have a test light?

 

been a bit busy with work this week, however Im replacing the fuse in the taillight slot of the fuse panel with a 20 AMP (yellow) fuse.

I do have a test light, however havent had time to mess with it this week.

 

Alright. First, there is a fusible link 'linked' to you're headlight switch. Remove the switch, and follow the RED wire.... and check to see if the fusible link is still good. If okay, then there are a number of other wires you'll need to check from the switch.

The ORANGE one is constant power, and since you're blowing fuses when turning on.... lets assume you're getting juice.

The BLACK is obviously the ground.

The YELLOW is directed to both the 'Headight Doors Module', and the 'Headlight Dimmer Switch'...

The BROWN (which is what I'm going to guess is the culprit.... mainly cuz it routes to the Convenience Center, where there are additional fuses), routes to the Convenience Center, Fog Light Switch, Headlight Doors Module, Then all the way back to you're entire rear light panel....

The WHITE is directed to both the Map Lights, Dome Light, Left Door Jamb Switch & Right Door Jamb Switch....

But before we get deep into the harness, quickly check you're Convenience Center found behind the ALDL panel....

 

just to post an update if anyone cares.

I now have working lights on the car. after removing the side kick panel, looks as if a previous owner hardwired a mobile phone into this circuit and when they removed it, never bothered to take out the wiring.

My right blinker still does not 'blink', however this is a fairly minor inconvience for the time being. Hazards work and left side works.

thanks a ton for all the suggestions.