New wiring dosnt do anything when key is on.

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randomTruckKid

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Finally got to the point where I can try to test my new wiring. I wired pu the frame with the body off. Then yesterday I put on my new cab, from a 1984 c10.
Been wiring it all day today but I try to turn it on and nofthing happens.

Currently the only thing on is the cab. So no exterior lights. Really what I'm looking for to happen is the gauges to light up. Nada.

I can't put on my front rad mount till Tuesday bc I am waiting on body mounts.

Now I have to ask. Do I need to have generally everything together for it to work? I've alrety gone checking the 2 ground wires in the back of the cab, had to attach both.
 

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Dmack

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If it's an aftermarket harness, I would guess that if you have the main power input hooked up to the new fusebox, a good ground, and a complete circuit with fuse, that circuit should work. If it's a factory harness, check the fusible links as they feed most of the circuits.
 

Dmack

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Just remembering, I think the headlight circuit doesn't work like a traditional circuit. Something like it's the ground side that is switched , so if you were trying to use a different harness, it's tough to integrate the two. Could be way off, so hopefully those more knowledgeable will chime in.
 

randomTruckKid

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If it's an aftermarket harness, I would guess that if you have the main power input hooked up to the new fusebox, a good ground, and a complete circuit with fuse, that circuit should work. If it's a factory harness, check the fusible links as they feed most of the circuits.
Guess I never said when I made the original post. It is all new harness. 27 circuit painless performance one.
 

ali_c20

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I vote for ground. Have you temporary grounded your exterior lights to the chassis/ body ? Ground connection from chassis/body to battery ? On the 3rd picture of the original post there is no ground connected to the battery.
 

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A test light will do wonders.
 

randomTruckKid

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Where all is the cab supposed to be grounded? All I have/know of is the 2 wires in the back of the cab that jump to the frame.
 

Jgonick

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good info here
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Zelph

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Is there power at the 10 amp fuse labeled “gauges”?

Start there and work your way through the gauge circuit until you find no power.
 

randomTruckKid

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So I've done some testing and fixed my grounds.

But I think I have a short somewhere? Info is a little confusing. It seems I shouldn't be getting a reading or when I touch the positive and neg cable with my ohm reader. (The key off)
You must be registered for see images attach

But I did (as you can see ablove) it's on the m ohm setting.

I unplugged my block between the cab and exitior harness and the resistance shot up to 2.1
You must be registered for see images attach

So any of yall have any ideas? Most likely I'm completely wrong here.
 

ali_c20

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Try the same test with the buzzer of the multimeter. If there is a short it will beep.
Have you checked all the fuses?
Members with better knowledge about electrics can help you more as I can.
 
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Ricko1966

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So I've done some testing and fixed my grounds.

But I think I have a short somewhere? Info is a little confusing. It seems I shouldn't be getting a reading or when I touch the positive and neg cable with my ohm reader. (The key off)
You must be registered for see images attach

But I did (as you can see ablove) it's on the m ohm setting.

I unplugged my block between the cab and exitior harness and the resistance shot up to 2.1
You must be registered for see images attach

So any of yall have any ideas? Most likely I'm completely wrong here.
If there is anything connected to the harness positive and harness negative,that is not switched off,you will show a reading on ohms scale at the battery terminals the circuit is going from your negative meter lead down the negative cable through whatever you have connected to positive and negative in the truck then through the positive cable back to the meter to create a complete circuit,not an open curcuit. With nothing connected to positive and negative in the truck you should read open at the cables.so disconnect one wire from everything you have connected in the truck,unless it's switched through the ignition switch. If you have no loads connected and the ignition switch off you should read open at your battery leads. If not,then you have a short. Fuses will not cause your problem,and the buzzer of the multimeter will sound for continuity,so not a valid test for what you are doing.
 
Last edited:

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