I have a '73 that was originally a 1.7 but now has a carbureted 2.0. The EFI harness is gone and so is the head temp sensor. I have a head temp gauge and would like to install a new sensor. This car does not have the center console or harness in the tunnel. I would like to mount the gague on a gauge holder under the dash above the tunnel. The question is, how do I wire this thing up? I have the same situation with the Oil Temp Sensor if anyone could help with that as well.

Most of the aftermarket CHT gauges use a "ring" sender that goes under a spark plug. Put it on cylinder #3. Also note that most specify that you don't cut the wire... if it's too long, coil up the excess.

What I ended up doing is running the wires up the left-side air tube. I used a fishtape and bundled around 8 wires together inside some expandable sleeving and then fished it from the front to the back and then ran the front wiring thru the grommet where the washer hose used to go thru the front firewall and then ran the rear wires up thru where the rain tube used to go. the head temp sensor, if it's a VDO, the RED goes to NEGATIVE the BLACK goes to POSITIVE. It makes no sense, but the manual that comes with it IS CORRECT. I'll post pics if you really really want them

I thought the sensor had only one wire. I figured that would have to be run to the gauge and then a switched power source would have to be run to the gauge as well. Am I way off base here? If not, where is the best place to pick up my power source?

One wire from the sender under the spark plug to the gauge. No power source. Then a ground.

The switched power source would only be used for the light bulb if you want it illuminated - that's a separate circuit.

the factory feed to the oil temp wire is located by the battery and comes out somewhere under the dash/console area. i forget the colors but offhand i think its black w/ green chaser.

this may help, keep in mind it's for duel cht...
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