Fuel gauge wiring help?

[Billys44s]

Hey guys,

I been working on the wiring on my 86 c10 over the weekend and I been trying to hook all the wiring back into the original harness and I came across the fuel gauge wires and I noticed there a wire ran from pin 7 to 18 and I don’t think that’s right but I wanted to be sure what wire goes to those pin so I can hook it up properly.

any help would be appreciated

the picture below is the wiring I’m talking about

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[dsteelejr]

Thats normal.

The pic below is out of the wiring diagram for 1980, but the gauge cluster wiring didn't change much '76 - '86. Circuit 30 Pink is for the fuel gauge. As you already mentioned, the fuel gauge circuit has two pins on the cluster pigtail, 7 and 18. The pin at slot 18 (bottom left in the wiring diagram) has two wires coming out of it. Wire Pink 30A runs from the cluster pig tail to the firewall bulkhead connector and continues outside the cab to the fuel tank. Pin 18 has another pink wire spliced at the pin, pink 30B, that runs to pin 7 on the other side of the connector, the looped wire you're asking about. One of my spare pig tails it has the same pink wire loop, too.

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[dsteelejr]

@Billys44s I wanted to add that you can find good used pigtails, like the one I have as a spare in the picture above, on eBay for cheap. They're going for about $20 to $25 plus tax and shipping. The one in your picture looks a bit hacked up and it can be hard to work with when you have butt connectors right at the connector pins. I'm in the process of rewiring my square and have had several instances where there's not enough wire left for another butt connector and it's frustrating as all hell.

What I decided to do, so I don't end up hacking up the connector wires to the point the connector is unusable, I put spade connectors on my pigtail wires so the connector is disconnectable. I also bundled up the wires that have multiples of the same circuit, like the wires for the fuel gauge, three wires for ignition power (pink & black), three ground wires (black) and parking brake / brake warning light wires (tan & white). I think I'm going to replace them with bullet connectors instead, but this way I won't have to keep chopping up, stripping and cutting away at the wires when I need to really get in there.

Good luck.

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[AKguy]

Here’s a color pic for an 81 with guages

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[dsteelejr]

Here’s a color pic for an 81 with guages

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That color diagram is sweet. Where did you get it?

 

[AKguy]

Yes, I have them for my Square and a 1979 F250 (grandson’s)

www.classiccarwiring.com

 

[AuroraGirl]

@Billys44s I wanted to add that you can find good used pigtails, like the one I have as a spare in the picture above, on eBay for cheap. They're going for about $20 to $25 plus tax and shipping. The one in your picture looks a bit hacked up and it can be hard to work with when you have butt connectors right at the connector pins. I'm in the process of rewiring my square and have had several instances where there's not enough wire left for another butt connector and it's frustrating as all hell.

What I decided to do, so I don't end up hacking up the connector wires to the point the connector is unusable, I put spade connectors on my pigtail wires so the connector is disconnectable. I also bundled up the wires that have multiples of the same circuit, like the wires for the fuel gauge, three wires for ignition power (pink & black), three ground wires (black) and parking brake / brake warning light wires (tan & white). I think I'm going to replace them with bullet connectors instead, but this way I won't have to keep chopping up, stripping and cutting away at the wires when I need to really get in there.

Good luck.

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If you are gonna do frequent disassembly of that connection point, a connector lubricant should be used that is good for tin covered crimp connectors. if you had any repeat colors, you could even reverse the direction of the splicing to further aid assembly by only allowing the proper wire to wire match. But i think you only have a couple grounds that match?

nice

 

[dsteelejr]

If you are gonna do frequent disassembly of that connection point, a connector lubricant should be used that is good for tin covered crimp connectors. if you had any repeat colors, you could even reverse the direction of the splicing to further aid assembly by only allowing the proper wire to wire match. But i think you only have a couple grounds that match?

nice

Appreciate the advice about connector lube. I hadn’t thought of that.

If I understand what you’re saying, if there are multiple wires of the same color that go to different circuits, reverse the male / female connectors so it is sort of keyed to reduce the likelihood of connecting wires to the wrong circuits. That’s a great idea, but with gauge cluster pigtail there are no wires multiples of the same color wire that go to different circuits. There are multiples of the same color that plug into different slots on the pigtail, but they are for the same circuits so it doesn’t matter. The three pink & black wires are an “ignition on & crank” power feed that sends power to the gauges that need it for senders, as well as where the volt meter gets its reading from. The tan & white wires split and one end goes to the parking brake switch and the other goes through the fire wall to the brake failure warning light switch, but both splice into the brake warning light. Same goes for the fuel gauge wire that was the original question in this thread. And there are three ground wires on the pigtail, which I have also bundled and spliced together into one spade. So it doesn’t matter which one goes to which.

 

[K5ride]

Yes, I have them for my Square and a 1979 F250 (grandson’s)

www.classiccarwiring.com

The color, laminated wiring diagrams are fantastic. I got the larger "poster" size for my 75 stepside and have it on the inside lid of my roll away toolbox, held on with magnets. It's easy to see and easily accessible. The colors in the diagram follow the factory wire colors so it is easy to use. My eyesight is not what it used to be, and I have a hard time following the wire paths on the very small black and white wiring diagrams. They make great gifts too. I'm getting a friend one for his 70 GTO.