Hello, my cars previous owner had cut up the harness pretty good. I cant track down the water temp sensor wire and i want to fix it without adding another aftermarket gauge.

A couple questions to point me in the right direction -

What color is the wire?

What circuit does it run off of and which group of wires is it usually strung together with?

Does it run to the ECM (my car is now carb) before it routes to the gauge?

If i get a new sensor and sender, where can i run a wire to in order to get an actual reading?

Any help, greatly appreciated!

 

Hi Patrick,

I assume you are asking about the wire for the temperature gauge sensor, not the ECM temperature sensor.
The temp gauge wire comes out of the firewall via the C100 connector and splits out of the loom pretty early, going to the driver side head (between the first two spark plugs). It is dark green in color and it is just a single wire, usually with a flat spade female connector.

If you find a dark green wire in your loom, you can test it easily (with ignition on):
- disconnected wire will indicate full hot on the gauge
- grounded wire will sweep the gauge to full cold

Hope this helps.
Lou

 

Hey Lou,
Thanks for the reply.
Yes I meant the coolant temp sensor. I see the small green wire coming out of the c100 then it disappears into the loom, which is now taped and wrapped up. If I turn the ignition the gauge reads as full cold and doesn't move.
Can I just get a new sensor and wire it directly into that green wire as soon as it comes out the c100? If the end of that wire is grounded once I cut it should be good, right?
Thanks for the help Lou, it's appreciated.

 

As I mentioned in your other thread, I made a mistake and said the wrong gauge state.
If the wire is disconnected, the gauge will read full cold. With the wire grounded, it will read full hot.

Sure, you can cut the green wire where you see it by the C100 and run a new piece of wire to your sensor. You can also pull the wire out of the loom (just slide it out, if it lets you).