Any chance someone can send me a pic of the yellow green wire and plug it comes from. That goes to my temp sensor for gauge cluster? Currently don't have the right wire on it and only yellow green I have found is cut off at plug.

Thanks

 

id liker to see this diagram too my temp and oil pressure wires have both rotted away

 

I’m having the same issue. I’m trying to get my temp to register on the dash and all my wires are cut. I’ve tried the yellow wire with the green stripe but not showing anything. I’d like to confirm this is it before going further.

Is this it?

 

I have two yellow with black stripe at this plug. Only one of those comes out the other side. The one beneath the yellow/green is going to my oil sensor located behind the oil filter

 

Alright! I figured it out. This is the wire. It goes to the spade connector sensor. My sensor is bad. Grounding this wire confirmed the reading on the gauge. Ohm meter on the sensor itself was all over the place.

 

so i only have the spade connector and the sensor in a 79 it has no ground or green plug it should still function? right? whats the way to test if its the wire, gauge, or sensor?

 

when you ground the spade connector your gauge should go to max temp if the gauge is working

 

I tried testing my existing sensor with a multimeter and got a wide range of results. I don’t remember what the readings were but they were not consistent at any temp. When I grounded that wire with the ignition on the gauge went to max so I figured it good. Then I installed a new sensor and chopped off that green connector, sliced in a wire and put a spade on it. Temp is reading correctly now.

That is the only wire that goes to the sensor. It is the ground and varies it’s connection based on the temp.

Im learning that a lot of the electrical on these trucks are ground switched rather than positive switched (such as headlights). Something new to get used to if your like me and think about electrical systems always being grounded and positive switched.

 

awesome! thanks
ill have to just check the actual vs guage

 

As soon as I turn my key the temp goes to hot. Does that mean that the wire is grounded somewhere? I'm lost when it comes to electrical. Thanks.

 

goes to hot and stays hot? or just "flexes its muscles" and retreats back to cold?

 

Goes to hot and stays there. Instantly.

 

check the connection via voltmeter or even just unplugging it and at least figure out if its the gauge or the sensor

if its the sensor, get a new one they are easy to replace and not hurt the wallet too bad

if its the gauge revert to voltmeter or tracing and checking connections and wire all the way back to the dash

 

Thank you very much.