Can anyone in Atlanta help me? Electrical

[stingray72]

Ok.. I'm at my wits end.. I'm at the only thing that's keeping my truck off the road.

I found out my headlight switch was bad so my rear lights weren't working. Well I replaced the switch and now it's blowing fuses. The rear lights will come on if you power it at the fuse panel. I'm fed up, tired and just want a running truck

Wiring and Electrical is definetly not my thing but I'm want to learn. obviously doing it myself is proving to be VERY SLOW.

So this is my proposal. I'm willing to compensate anyone for some help. You need something towed, moved, want me to take your hot daughter out on a date (j/k) whatever. Or if you just want some money that's fine. I just want to learn how to diagnose this so I can do it on my own in the future.

Anyone got a little spare time and some know how to help??

[72freak]

Have you checked the circuit board on the instrument cluster to see if there is any burned, shorted or smoked parts? Unplug the main harness to the cluster and see if there is any smoked contacts there. You will have to disconnect your oil guage line.

Where ever the short is...it is probably why the headlight switch was bad to start.

Did you use a new or used headlight switch?

[stingray72]

I used a new headlight switch.. All of this was working find before I changed beds on the truck

I haven't checked the circuit board on the gauges

[67ChevyRedneck]

Does the fuse burn out if you just use the brakes and turn signals (headlight switch off?) Does it burn out immediately? Does it take a while? Does it burn out when you do something specific (like hit the brakes or tun on headlights?). I'm not too good with elec stuff either but I know a tad bit about it.

[67ChevyRedneck]

Originally Posted by stingray72

I used a new headlight switch.. All of this was working find before I changed beds on the truck

I haven't checked the circuit board on the gauges

Have you checked to make sure the lights have a good ground? If you have to, take a wire that stripped on both ends and touch it to a bare spot on the frame and the taillight bucket. Also, for the taillights, they should both share one brake/taillight wire and have individual turnsignal wires. The tag light runs off of the brake/ taillight wire as well.

[stingray72]

Fuse is fine with the turnsignals and brakes. They will work with a bad headlight switch.

Fuse blows when I turn on the lights. Before, when I turned on the lights, the headlights would come on but the tail lights wouldn't

[stingray72]

Originally Posted by 67ChevyRedneck

Have you checked to make sure the lights have a good ground? If you have to, take a wire that stripped on both ends and touch it to a bare spot on the frame and the taillight bucket. Also, for the taillights, they should both share one brake/taillight wire and have individual turnsignal wires. The tag light runs off of the brake/ taillight wire as well.

The first thing I did was grounds and even ran an extra

[pkj]

put on a new bed? i would be cheaking everything back their. pinched harness, mis alighned connections where harness comes thru rear crossmember. rember old harness may be brittle.

[stingray72]

My hunch is I'm going to have to take the bed back off and check the wiring running in the frame... *sigh*

[pkj]

no. just get under there and look and feel. unplug harness at rear crossmember. if fuse stops blowing problem is at rear only.

[stingray72]

I relocated the tank and can't get to the wiring in the frame rail now :-/

[72chop]

where are you in atlanta? i am rewiring my 72 this weekend and if you can come to douglasville i can take a look at your problem. call at 404-259-4167

[stingray72]

I'm in Tucker. I could head over that way on Sunday. I've got a little time in the morning to try out some things so I'm going to see what I can do. Can I give you a call tomorrow afternoon if I'm unsuccessful??

[72chop]

i will be working on my truck both days so call me. i am putting an EZ wiring kit in mine so i have realy checked out the wiring. i am also working on my 1 piece window kit and doing body work.

[mac]

What happens when you remove the tail lite bulbs and turn the lights on ?

What happens when you pull all of the running / turn bulbs and turn it on?

What happens when you step on the brake when you have the bulbs removed?

What happens when you remove the headlite connectors, turn the lites on after you do all of the above?

If you blow a fuse with the lites removed you have a shorted running or brake lite wire and you need to look where you last worked. Step backwords a one move at a time and Murphy's Law says, it'll always be the last place you look !

I'd start wherever you made the wire connections after the bed change.

If it worked before the bed change, you caused it ! You'll need a meter and some time but be logical when you track it down. It may be as simple as a hot and ground term crossed.

Pay me now or pay me later, its Murphy's Law!

[truckdude239]

if you didn't have the problem before replaceing the switch i'd take it back and get another to emilnate the chance of a bad light switch even if its new

[stingray72]

Originally Posted by mac

What happens when you remove the tail lite bulbs and turn the lights on ?

I haven't tried.. I will try tomorrow

Originally Posted by mac

What happens when you pull all of the running / turn bulbs and turn it on?

again.. haven't tried, will do so tomorrow

Originally Posted by mac

What happens when you step on the brake when you have the bulbs removed?

It works fine with the bulbs in, would it be any different when the bulbs are removed?

Originally Posted by mac

What happens when you remove the headlite connectors, turn the lites on after you do all of the above?

dunno, will try

Originally Posted by mac

If you blow a fuse with the lites removed you have a shorted running or brake lite wire and you need to look where you last worked. Step backwords a one move at a time and Murphy's Law says, it'll always be the last place you look

I've only worked around the bed area. Nothing else and everything worked before I took the old bed off.

Also.. if I keep looking once i've found the problem i'm just going to quit all together

Originally Posted by mac

I'd start wherever you made the wire connections after the bed change.

will do

Originally Posted by mac

If it worked before the bed change, you caused it ! You'll need a meter and some time but be logical when you track it down. It may be as simple as a hot and ground term crossed.

Pay me now or pay me later, its Murphy's Law!

I figure I caused it... i break most everything i have

[72freak]

Originally Posted by pkj

no. just get under there and look and feel. unplug harness at rear crossmember. if fuse stops blowing problem is at rear only.

yep...........try unpluging the rear harness and then turn the lights on.


Good call

[VetteVet]

You have pinched the brown wire which powers the taillights and the marker lights and the license plate light, or else one of the wires that feeds them off the brown wire is shorted to the ground.
The brake and turn signal lights share a common wire for each light . There are only four wires that feed the rear lights.
1. yellow for the left turn/brake
2. dark green for the right turn/brake
3. brown for the tail/license/marker lights
4. light green for the backup lights.
hope this helps