Ok gents, I did the search and have already replaced the headlamp switch. My tail lamp fuse continues to blow when I turn the headlights on. Headlights work fine, taillights, gauge cluster doesn't. Is there anything else to check or do I start searching for a short? I could use some guidance on searching for a short also. I'm a fairly decent mechanic but dont know Jack when it comes to electronics.

 

For some odd reason this happens to a lot of us, me including, i just replaced the fuze, go over all the grounds from the drivers side wiring harness and make sure that they are clean adn good, replace that fuze adn see what happens

 

If that fuse blows, you should also not have any parking lights or marker light either. What size fuse are you using in it. I would also check my tail lights, marker lights, and parking lights to see if one of them has shorted out which would cause that fuse to blow.

 

Trickster - Youre right on the money, none of those lights work. By saying, check to see if one of those lights has shorted out, do you mean to physically check each light bulb? I'm using the prescribed 20 AMP fuses. I have a multimeter and know how to check volts/ohms but I'm not sure what to check?. Are these lights wired like the freaking xmas lights, when one goes they all go?

 

Hi IROC Magman-
With electrical shorts, there is no saying- it can be any of a 1000 things.
Here is what happened to mine (I copied this from a previous thread I started).
"I found the electrical short I had.

Symptom: I went over a bump and my dash and running lights went out. Then, intermitently, my running lights would go out when I stepped on the brakes.

Cause: The huge wiring bundle under the dash (just before it joins into the fuse box) was rubbing on a brake pedal bracket for 110,000+ miles (_insert 4-19-04_ there is a goofy little bracket on the brake pedal- it looks like a bracket to hold a switch or something. This is what was rubbing on the wire bundle). It finally wore through and was shorting out this huge 12 ga. wire in the middle of the wire bundle every once in a while. It seems that one time it got hot enough to melt through an adjacent wires which caused a short everytime I would step on the brakes.

Fix: Laying on my back, upside down under the dash for 4+ hours cutting and soldering wires back together. The heat melted the insulation off a total of 4 wires and browned approximately 8 wires (most of those did not require a fix).

That sucked.

Anywho, just one thing to check if someone is having an electrical problem.

Terms for future searchers: Wire brake parking running light lights short electrical wiring harness parking blown fuse pissed off pulling hair out
"

Please post your fix (whether it be the same for you as it was for me) for the benefit of others...... electirical shorts suck a$$.

I've been there and am perfectly serious when I wish you g*dspeed with your fix.
Best-
S-D

I should mention- my symptoms are not exactly the same as yours.. but any of the wires you mention could have fused together if your short originated in the same spot as mine.

 

I had a light problem a while back, where my rear lights were really dim and my headlights didnt work at all. What I did was take my multimeter and check for 12v at the headlight plug, no power there, then check the rear lights and got around 4v, but I hit the body with the negative lead and they all came on. Dug around a bit and found a ground wire over by the trunk motor broken off. Dont think that directly correlates to your problem, but might give you a place to start looking.

 

Okay, basically what will happen is that if there is a bulb or something causing a short at any one of those lights, it will blow the fuse and kill power to all of them. Another couple of items that are in that circuit are the fog light relay, the audio alarm assembly in the convenience center. The guage cluster lights use the INST LPS fuse which is tied into the headlight switch.

 

Part 1

 

part 2

 

Trickster, Thanks bro. I'm going to recruit the talents of my neighbor to help me out. He's an electronics technician in the Navy. With his experience we should be able to put this one to rest.

 

Found the short. The wires to the left license plate light looked like a rats nest. Melted and severely frayed. Just so happens it was the last light I checked, doesnt it usually go that way..... Thanks for the help, IROCS on the road again!

 

Cool! That beats the heck out of lying upside down under a dash!
Thanks for posting the cause-
S-D

 

Sorry to dig up old threads gents, but this one seems to be right up my alley with a problem I am having.

problem: In short, my headlight switch will engage my starter when I have all fuses present.

Variables
- When the fuse that controls the tail lights is removed, the problem does not occur.

- This problem has also occurred when the entire rear taillight harness was disconnected.

We have removed the gauge cluster and dug into the wiring from the switch. This is what we've determined so far.

Please pardon the grain behind the pics as they were taken with a cell phone.

This is the harness for the headlight switch


These are the wires

(brown in this pic is the one between the yellow and orange wires)

When jumpering from the Red (hot) to the brown wire, the starter engages.

Orange wire - ?
White - Common
Red - Hot
Yellow - Headlamps
Brown - (this one shorts and starts the ignition)/ taillights
Green - Interior lights + chime
Blk - Ground

What I am needing to know is what else that brown wire controls (if anything else) I am also wanting to know what orange wire is for ? (is that for the gauge lights ? )

Any help you can provide would be greatly appreciated. Additionally, Trickster, do you have a better quality pic of that schematic ? (its been a big help so far)

Thanks for any help or suggestions you can provide.

 

orange = tail fuse
red = hot
white = interior lights
yellow = dimmer switch
brown = lights,, radio, & more
green = Inst. fuse & becomes a gray wire for inst. panel lights
black = ground

You forgot the gray wire which goes to the instrument lamp fuse. These wire colors are for a 87 camaro. I will scan the schematics and send them to you tonight by e-mail. Right now the significant other says I have to take her shopping so my wallet can go on a diet.

 

You say the brown goes to gray wire. From this point what else interconnects with the gray/brn wire?

Is it normal for the starter to engage by jumpering the Hot red wire to the brown wire on the headlamp switch plug?

If not wouldnt this mean that there has to be something connected on that circuit that is feeding power to the starter without having to turn the key?

Could this be caused by a kill switch? What would I look for in tracing this out further? I was thinking I should take a look at the wires going to and coming from the starter as well.

Any advice?

 

Also, when jumpering the red to brown the taillights flicker on and off.

 

One thing you have to remember here is that the red wire is a fusible link going straight to the starter solenoid and it also goes to the fog light relay. You might also want to look at the dimmer switch which is located above the ignition switch on the steering column under the dash. I am sending that schematic to you in an e-mail.

 

What manual did you get these from again ?

Im off onto todays (tonights) venture with newly gained knowledge and determination. I'll let you know what I find at the end of the night. Hopefully its something stupid at the tail lights, that would make my day

 

I got the schematics from the 1987 GM service manual wiring schematics. The manual is available from WWW.HELMINC.COM for $75.00 + shipping. Or you can search e-bay and bid on one there when they are available.