Tracing Thermostat wire Help

[Ichversuchte]

Hello,

I bought a 84 K10 last year which has been fun project. I changed out intake, radiator, leaf springs, shocks and more.

When i swapped out the old intake there was not a thermostat to be seen or a wire. I don't mind not having one but i have a gauge in the dash and i sort of have OCD about stuff not working.

I looked up some old diagrams of the wire harness behind the dash and believe its the bottom green wire shown here:

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That then goes behind the fuse block

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And i would suspect it goes behind the firewall but im not sure which wire it would be.

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What is the best way to get the original gauge working?

Appreciate the help.
-B

 

[PrairieDrifter]

The green wire should come out of the main harness behind the block on the drivers side of the distributor, it should then run over the drivers side of the intake and down on the side of the drivers side head near cylinder 2.

 

[75gmck25]

Look for the green wire where prairiedrifter described. Someone may have cut it off, or I got too close to the exhaust manifold and was burned.

The last 6-8 inches of the wire should have a protective cover. You run the wire along the retainers on top of the valve cover and then jog straight down near the center of the exhaust manifold to connect to the sensor in the head.

Bruce

 

[AuroraGirl]

If you do valve cover gaskets dont pull a me and sandwich the wire in the valve cover.

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[Ichversuchte]

Thank you for replying.

Isn’t that wire which is between spark plug 1 & 2 the oil pressure?

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I am trying to hook up the temp gauge which I believe is on the front of intake.

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I don’t see any single wires coming through the firewall other than the rpm tack wire which was after market and that runs into the top of the distributor cap.

Is that green wire behind the cluster the right wire?


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[crpntr78]

No, that's not the oil pressure sender. It is at the back of the engine, driver side of the distributor. In the picture you have shows the temp sender for the temp gauge.

 

[Ichversuchte]

Oh, so that is the wire which maps to this gauge? Sorry im being dense...

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[AuroraGirl]

mine is hard to see and full of grime(it IS green) but you see how it snakes around back of motor? its what i was trying to show you
Mine is obviously not run correctly but it is there.

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[Bextreme04]

The only engines that I have seen with a temp sensor in the front of the intake near the thermostat are running electric fans and using that sensor to turn fans on/off. My L29 454(MPFI) has both a sensor in the head for the gauge to read and a 3-wire, 5v reference, sensor in the intake manifold before the thermostat to tell the ECU what the coolant temp is to actuate the fans and control fueling.

 

[Ichversuchte]

Thanks for all the help everyone!

 

[PrairieDrifter]

This is your oil sending unit, near the back of the block, on top, by the distributor. You can see the ignition and temp wires snaking off from the main harness.

The sending unit you pictured is indeed the temp sender. I am not positive where it runs to inside the cab. Either the fuse block or straight to the gauge or both.

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[75gmck25]

I tried to get a picture of the green temp sending unit wire where it runs to the back of the engine, but all I can see is it disappearing into the harness that is below and behind the HEI. According to the wiring diagram it runs directly to terminal #35 on the dash temp gauge.

When looking for green wires, don't get it confused with the A/C clutch wire. That runs from the A/C plenum on the passenger side, across the top of the firewall and over to the A/C compressor on the drivers side.

Bruce

 

[Ichversuchte]

I found the sensor and replaced it. Ran the truck until the engine was hot but the gauge didn't move.

What is the best way to test if its the sensor, connector, wire along the way or the cluster itself?

 

[Ichversuchte]

I found the sensor and replaced it. Ran the truck until the engine was hot but the gauge didn't move.

What is the best way to test if its the sensor, connector, wire along the way or the cluster itself?

I got it all figured out now. Thanks for everyone’s help.


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