Temperature sensor with light.

I just ordered a temp sensor for my 65 289 with idiot light and received this:
tempswitch.webp


Is this the correct part? There was no sensor on this engine and all my other cars have a gauge.

Since most sensors simply sink to ground I was surprised to see two terminals. Does the idiot light require a ground or 12v source from the sensor to operate? All of the schematics I have show a single terminal type sensor. Assuming an over temp condition closes a contact between the terminals I'll just connect one to ground and the other to the light (or one side to +12v if a source is required).
 
i believe that the sending unit you got is for cars that have a cold warning light as well as a hot warning light. my old 68 ford custom 300 had that system. it let you know when the engine was up to operating temperature. test it to be sure though.
 
i believe that the sending unit you got is for cars that have a cold warning light as well as a hot warning light. my old 68 ford custom 300 had that system. it let you know when the engine was up to operating temperature. test it to be sure though.

Interesting. I took a closer look and one terminal is marked H, the other C. Armed with a heat gun and multimeter I tested both sides. The C terminal opened after a short time under the heat gun. The H side closed after a minute or so under the heat gun.

If it fits, It will work.

Thanks for the info.
 
Interesting. I took a closer look and one terminal is marked H, the other C. Armed with a heat gun and multimeter I tested both sides. The C terminal opened after a short time under the heat gun. The H side closed after a minute or so under the heat gun.

If it fits, It will work.

Thanks for the info.

then have a little fun and hook up a cold light to go alone with the hot light.:nice: