Heat gauge does not work. Where is the wire?

[Skunksmash]

In my 87 Silverado, the heat gauge does not work. Now, i have identified what could be the problem. There is no wire going to the sensor in the cylinder head. HA! Anyway, the only thing is, i can not find that little wire! can someone maybe post a pic of where it comes out of the firewall, or wiring harness? Also, is that the only sensor for heat? What is that little sensor at the very front of the top intake manifold? It looks very similar to the heat sensor in the side of the cylinder head.

[VileZambonie]

The temp sending unit wire breaks out of the harness near the lh side top of the engine. The sensor in the intake manifold is the engine coolant temp sensor for the ECM

[Skunksmash]

Left hand. Thats as if you were facing the engine compartment from the front of the vehicle, correct? So it kinda has to run across back behind the distributor? I ask cause i can not seem to find the wire.


Are there any after market heat gauges that come with a new wire just in case the wire is gone?

[ccz145a]

Left as in sitting in the cab. Directions are always in relation to the driver sitting in the driver's seat.

[Skunksmash]

Thats why i usually say driver or passenger side. Helps clear up any confusion.

[VileZambonie]

Drivers side is the LEFT hand side. Passenger side is the RIGHT hand side.

[ccz145a]

I prefer PORT and STARBOARD myself

[Skunksmash]

I am starting to think my wire may be missing. Would someone be so kind as to post a pic of exactly where it comes out at? I cant seem to find it anywhere.

[Skunksmash]

Sorry if this shows up two times, but i guess i messed it up on my last try. I would like to BUMP this up for my last question. I need to get that guage working.

[DnStClr]

I think you should be looking for a dark green colored wire.

[ccz145a]

dark green and either 16GA or 18GA (thin). Of course it's never that easy, my temp wire in my 75 has a white asbestos wrapping.

[DnStClr]

Here's some pics- the wire goes down along the lower side of the L/H head..




It comes out of the harness behind the master cylinder at the left side of it-

[Skunksmash]

Dang the photos got deleted before i got to see them. Anyone got any other photos?

[DnStClr]

Wow, I don't know how the pics got removed Skunkmash. But anyway, the green wire from the temp sensor in the head (near the 2nd spark plug on the driver's side of the engine) travels down the side of the block toward the rear of the engine and joins a wire bundle there. The wire's dark green.