Really odd electrical problems

[NorCal_Chris]

So the 73 blazer i recently picked up had very very dim instrument lights... So i was like ok i will pull this off and replace the bulbs/led or whatever like ive done with my other cars.

So i start looking around and the stick on circuit on my cluster is all peeling off. some lights work in some spots. other spots they dont. Tach has some random connectors on it leading to a bunch of wires not connected to anything.

so i have no clue what to do with that mess.

But here is the main issue. Blinkers work, click and work outside. right blinker indicator does not flash in dashbut left does.
with lights on blinkers do not work, left blinker indicator does nothing, right blinker indicator does nothing, but the cluster lights blink.

hazard lights work, but with lights on they dont.

with lights on the right blinker indicator light is on, always.

amp gauge seems to stay in middle always.

it doesnt seem like the main cluster harness has been messed with. Should i go to the wrecking yard and try a new cluster and ditch mine? i dont even know were to start.

 

[RootBreaker]

Should i go to the wrecking yard and try a new cluster and ditch mine? i dont even know were to start.

yes... I say this as you should just find one in GREAT shape and have that as a starting point.. from there you would be good to go...
then work backwards...

 

[shaun89]

what he said!

 

[NorCal_Chris]

a closer look at the back of my cluster and one of the circuits has a fried area. im gonna try and solder a wire to bridge it and see if that works. a new cluster is 40 bucks at pick and pull and that is kinda lame. so we will see if this helps.

 

[Russell]

Check the integrity of the ground wire coming off your main harness! It is a single black wire coming from the main harness heading up off the fuse block to your instrument cluster, heater controls etc, and is bolted though an eyelet to the center of the grounding block on the top of the park brake assembly to the left of the instrument cluster.

The symptoms you've described are classic symptoms of a damaged, missing, or poorly connected grounding wire. If the burnt out path on the circuit sheet is for the grounding, then you'll have found your issue right there!

 

[oakknight]

Definately find the cause of that circuit to burn out before putting it back in .. has to be an underlying condition.

 

[NorCal_Chris]

Definately find the cause of that circuit to burn out before putting it back in .. has to be an underlying condition.

well it wasnt exactly burnt, it was old and crusty and not connected anymore.

I soldered a new wire in its place and my instruments light up

but tonight i noticed something that i didnt before lol. when i hit my brakes my brake lights light up but so do my cluster lights, and parking lights lol. any thoughts on what could be linking those two?

this happens of course only when my lights are off.

 

[Fordum]

Again grounds. What it happening, is that you are putting 12 volts to the brake lights, but they are not grounded properly. So the power is going through the filaments, and through the instrument panel to ground. Remember, the tail and brake lights share a common ground. If that ground is bad, then the power goes from the brake light to the tail light, since they are hooked together at the case, and then to the panel.
As I vaguely remember, there is a ground connection for the tail lights in the harness under the back bumper somewhere. Someone who has worked on one of these withing the last 10 years or so, unlike me, should be able to chip in and say where.
But, if you just get under the back and look at the harness going from one side to the other, you should be able to see the loose wire.

J.

 

[NorCal_Chris]

Again grounds. What it happening, is that you are putting 12 volts to the brake lights, but they are not grounded properly. So the power is going through the filaments, and through the instrument panel to ground. Remember, the tail and brake lights share a common ground. If that ground is bad, then the power goes from the brake light to the tail light, since they are hooked together at the case, and then to the panel.
As I vaguely remember, there is a ground connection for the tail lights in the harness under the back bumper somewhere. Someone who has worked on one of these withing the last 10 years or so, unlike me, should be able to chip in and say where.
But, if you just get under the back and look at the harness going from one side to the other, you should be able to see the loose wire.

J.

Hrmm i didnt even think of that.... makes sense though!

I checked the ground near the parking brake and that guy is in good shape. I will scrounge around at the rear and see if i can come up with anything.

 

[Russell]

The tail light ground wire is found behind the tail reflectors. On a pickup there is only one, usually on the driver's side, on a K5 there is one on either side