Wiring issues

[thedxp]

Wondering if someone could help out?
I have a 97 Tahoe and recently had to have my alternater replaced. About a week after the work had been done my instrument cluster lights went out along with my running lights and tail lights. Brake, signal and head lights still work but nothing else. First thing I did was check the fuse, sure enough the fuse is blown. I replace the fuse and with the truck off I just turn on my head lights to make sure all is working. The second I turn the switch on the fuse pops...... Any idea where I should start my search for wiring problems.

Any help would be greatly apprecitated.

 

[Hardwarz]

When trying to troubleshoot an electrical problem that blows fuses, I suggest using a circuit breaker (The kind that replaces a fuse.) That way you don't have to keep replacing the fuse. From there, you have to find the short.

Hardwarz

 

[GMCYukalade]

I don't know if that would be alternator related - but id check out the headlight switch wiring harness to start - just pop the front of the dash off, pull out the headlight switch and look at the wires - make sure none of them have burned thru and are touching or grounding on a peice of metal

-Kinda OT- Wouldn't it be great if instead of a fuse box in a vehicle they put mini-circuit breakers in there - then you'd no longer have to buy fuses!

 

[Rick90467]

Your new alternator is putting out a better charge than the old one. Some of the older bulbs in your courtesy lights were ok with the weak alternator but could not handle the better voltage and may have fused inside the bulb, they sometimes still work but you will have to take one out at a time to see which one it is. Your dash lights are prob. fine, they are of much better quality circuit than the other lighting on the truck.

 

[thedxp]

Gents

Thanks very much for the advise. I now have an area to start the investigation.

 

[thedxp]

Gents

I am still having problems with the head lights tail lights and dash. I have checked all the interior bulbs and all seem to be fine. By that I mean I removed all bulbs and put in a new fuse. Soon as I turned on my head lights the fuse popped again. Then I removed the dash bezel and took out the plug that connects to my dash light switch. I noticed that one wire had a brown colouring to it and the plastic covering was very hard. This to me means that it was burnt. So I removed all that bad wire and tied in a new piece. Now before replacing the plug and putting back on the switch I kept that one wire (orange) out of the plug and put it back on the switch. I replaced the fuse turned on the lights and the fuse didnt blow. However the headlights worked but no dash or tail lights. So I then put the fixed ( or so I thought) orange wire to the plug and tried the switch again and pop goes the fuse. Does this indicate that the headlight switch is the problem?

 

[KarenCaren]

go check for wirings you maybe have a short circuit. or maybe your alternator give you huge charge that your fuse can't take it. Try getting a better fuse.



_______________
A Blog: Autopartswarehouse.com

 

[96ProCompTahoe]

sounds like you have a short.

does the truck have a trailer harness on it? if it does disconect it, and try the lights again.

 

[qlc1964]

You need to get a tester with the continuity that has sound to it so if you put one
lead on a wire and the other lead to metal it will make a sound.

quicker than watching
the readings on the meter.

 

[JKmotorsports]

Bad switch or wiring shorted somewhere. The output of the new alternator has nothing to do with blowing fuses. The circuit is only going to draw what is needed to operate, no matter what the output of the alternator is. Don't try installing a larger fuse, then you take the chance of wiring or electrical component damage or fire. The fuse is there to protect the circuit wiring from excessive current draw such as from a short or bad component.
There should be a brown wire coming out of the switch. When you turn on the parking light switch, that wire should get +12v to activate the parking light circuit. If that wire is grounded without being plugged into the switch, then you have a short in the parking light circuit somewhere. You'll need to check all the wiring in that circuit including anything hooked into the circuit such as trailer harnesses, aux lighting, etc. If not, then it's probably a problem in your switch. The orange wire you removed and replaced earlier provides 12v to the switch for the parking light circuit. If it gets grounded from either the switch or the wiring when you turn on the parking lights, then the fuse will blow.

 

[thedxp]

Wiring issues continue

Well my parking lights, tail lights and dash lights still don't work. Here is a run down of my diagosis to try and figure out why when I turn on my head light switch on the fuse blows. (number 9 20 amp)
Removed trailer plug, taped off all wires and tried the switch, blew the fuse.
Removed all of the exterior light bulbs, tail lights, license plate, and front marker and signal bulbs, blew the fuse.
Unplugged the main light wiring harness for the rear of the truck, blew the fuse.
Unplugged the main light wiring harness for the front of the truck, blew the fuse.
Replace the head light switch with a new on from GM, blew the fuse.
I am at a total loss.

Have I missed anything, could it be my day time running light relay?
I have a Haynes wiring diagram and have read it over and over.

Any help would greatly be appreciated.

 

[mygreen98]

sounds like short to ground on the brown wire. as JK said the brown wire is 12v + feed to the lights. using an ohm meter(hopefully u have one) remove the plug from the switch, and test brown wire to ground. if it ohms out, its shorted to ground. now you'll have to trace that wire arond the vehicle. did you change radio? or do any work in/around dash?

 

[JP422]

Any new updates on this issue? My dash lights don't come on sometimes... and when I turn the lights on manually (instead of leaving it on auto)... then they all turn on again... and I can go back to auto. It all depends on it's mood. Luckliy, no blown fuses yet...

Please keep us updated!!

Thanks!

 

[thedxp]

Wiring issues continue

Well, the still continues to this day. The only thing I have not done is completely removed the dash.
Is there a way to completely bypass the brown wires that run in behind the dash. There is just no room to move around and trace this wire. My thoughts were to run a new brown wire from the head light switch to the two plugs on the firewall in the engine compartment. You know the one plug controls the front half of the trucks headlight circut and the other plug runs the back tail light circuit. They are located below the brake booster.
I would much rather fix this problem the proper way by locating the problem wire but I just cannot find it. If anyone has any ideas or suggestions please by all means post. I am all ears.

 

[bsamoul]

No wires around the headlight switch are stripped are they and perhaps touching?

 

[95TwinTT]

With all that you have done so far, I would have to guess you are chasing a broken wire.

The most logical place for a wire to break is where there is movement. That brown wire goes to each of the four doors. Since the drivers door gets opened and closed the most, I would try cutting that brown wire in the area of the left front kick panel. You should be able to get at the brown wire before it goes through the tube into the door. It should be easy to snip it and have a solderless connector to put it back together if it makes no difference.

I know this is a long shot, but it is easier than ripping the dash apart. Lol

If you turn the rheostat all the way down, does it still blow the fuse?

 

[treepete]

you said the connector was burnt a little bit.. did it melt through to the next wire in the connector itself? pins bent or anything?

 

[zero]

My instrument cluster lights have a mind of their own also.....they come on when they want. I found the elusive problem last night. I noticed if I wiggle the dash headlight switch I can get the cluster lights to come on. I'm going to check for a loose wire, but I have a feeling that the switch is wearing out.

 

[JP422]

Hmm interesting... my exact symptoms are similar... Normally I don't touch the lights as they activate automatically when dark and parking brake is released... but once in a while the meter panel will flicker and turn off. If I rotate or joggle the light switch knob... then it will come back on and stay on for a long time again.

Good luck on the search.. and please post your finding here!!!

 

[thedxp]

wiring issue

Well gents.... Its fixed, after months of looking for wiring diagrams, chasing wires and a whole lot of cursing I found the problem. I ended up finding a wiring diagram that showed the brown wire that goes through the driver side kick panel that ends up going through the door and powers the lights that illiminate the power window switches. There was a bear spot touching one of the power window bars that move the window up and down. I can't thank all you guys that gave me advise enough. I will be posting tomorrow on this thread all the wiring diagrams and links that I have found trying to fix this problem.

Again gents thank you

Jason