1980 Starter wires?

[Trucksareforwork]

I did a search and looked at the wiring diagrams but haven’t figured this one out.

1980 C10, sbc with hei.

Pulled the motor a couple years ago and have forgotten this.

Four wires running through the metal heat shield to the starter. Colors are faded.

1. 2 fusible links to the main battery post.

2. 1 wire to starter/ignition post. It has a crimped spade on it.

3. 1 wire I have no idea about. Does anyone know this wire? It looks almost yellow?

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Any help?

 

[dsteelejr]

Aside from the heavy AWG battery cable to the starter, there should be a 12 AWG purple wire on the S post of the starter solenoid that is the signal from the key switch to crank the starter. There are two 12 AWG red wires that are attached to the primary power post. One wire goes to the junction block on the fire wall. The other is spliced into two wires, one feeds the constant hot to the alternator on the two prong plug and the other goes to the bulkhead connector. Once inside the cabin it splits again, one going to the light switch and the other feeds the constant hot side of the fuse block. Both 12 AWG red wires should have fusible links.

 

[Ricko1966]

I did a search and looked at the wiring diagrams but haven’t figured this one out.

1980 C10, sbc with hei.

Pulled the motor a couple years ago and have forgotten this.

Four wires running through the metal heat shield to the starter. Colors are faded.

1. 2 fusible links to the main battery post.

2. 1 wire to starter/ignition post. It has a crimped spade on it.

3. 1 wire I have no idea about. Does anyone know this wire? It looks almost yellow?

You must be registered for see images attach

Any help?

Trace it,see if it goes to the junction block on the firewall. I believe it does,if that's where it traces to,it goes to the 12v post of the starter.

 

[Chevy 88]

Continuity tests. See what goes where with key positions.

 

[Trucksareforwork]

Tracing it will be my next move. I just couldn’t make sense of the extra wire.

 

[Ricko1966]

Tracing it will be my next move. I just couldn’t make sense of the extra wire.

If your meter leads are not longbenough to check resistance from that lead to the junction block. Clamp that mystery wire to a metal to surface to ground it. Pull the wire off the junction block at the fire wall. With your multi meter in ohms scale,check continuity from the end of that wire to ground. If it is .2 ohms or less you've solved the mystery. Have the battery disconnected before you start this. Yes you need to disconnect the wire from the junction block for accurate readings. Alternatively you could take a reading at the junction block and then disconnect the grounded mystery wire and look for a change in resistance,but I do not know that that way is a sure thing.I know the first way is a sure thing. Clamping 1 end to ground and checking resistance to ground is a cheater trick for long or impractical situations ,like turnsignal switch to rear lamp socket etc. so you don't needing leads.

 

[Trucksareforwork]

Good advice. I dont have core support or battery tray so haven’t had the battery attached. I was wiring things up and getting headers in. Ran into the mystery wire!

 

[dsteelejr]

Thinking about it, the only time I’ve seen a yellow wire going to starter was for points ignition. It was to supply direct battery power to the point system while the engine was cranking. I don’t know why you’d have that on a 1980 unless the original owner ordered the truck with the HEI delete option and had points from the factory. Run it without the yellow wire and see what happens.

 

[xm20k]

I had a mystery wire it was the sender wire that went into the cab for the fuel gauge. I'm assuming someone melted it off and they looked at it and went comes out the harness right by starter stuck a terminal on it and bolted it on the main lug of the starter. Hmm wonder why the fuel gauge no longer works and the battery kept dying. They then fixed that issue by putting a disconnect on the positive battery terminal.

Guess what color the sender wire is? It's TAN.

 

[AuroraGirl]

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heres my 1980s starter shield... no colors visible tho!

 

[AuroraGirl]

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The non labeled wire in the photo is a black ,it goes to ground , which is a splice into another ground wire. i dont recall this running directly to battery , this is for a 83 tho, The PPL and RED (fusible link on red) are the only other ones. not sure this is helpful.

This is for 1980 but not very helpful:

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[Trucksareforwork]

I would be shocked if it was a ground wire.

 

[Trucksareforwork]

I did this trace this evening. It ended up being the fuel tank sender. I hadn’t realized that I was lacking that pigtail as I’m putting things back together. It’s a very dirty and faded pink wire running to number 30 on the bulkhead connector. I’m 95% sure of this and will confirm once I have gauges and power back in.

Thanks for the help. I didn’t realize the fuel sender wire would run in that same heat shield.

 

[83Stepper]

I did this trace this evening. It ended up being the fuel tank sender. I hadn’t realized that I was lacking that pigtail as I’m putting things back together. It’s a very dirty and faded pink wire running to number 30 on the bulkhead connector. I’m 95% sure of this and will confirm once I have gauges and power back in.

Thanks for the help. I didn’t realize the fuel sender wire would run in that same heat shield.

Yup, can confirm it's the sending unit from the fuel tank. They ended up running it through the heatshield with the starter wires because it's going from the frame to the wiring loom with the rest of the wiring that ends up going into the cab. Was the same on both my 77 and 83 C10's. Guessing it's just to keep it from getting smoked by the exhaust manifold? Who knows why engineers do the things they do at times lol.