Just wondering what the correct name for this scensor is, and what is it's purpose. If my car is non computer controlled, does it serve any purpose but plugging the hole. THe thing is broke in half and taped together, so I know it does not work now, but what is it suppose to do. Thanks in advance. Jason

 

temp?

 

yeah that looks like a coolant temp sensor.

 

appears someone was planning on using an external gauge/or using the sensor relay to control perhaps an electric fan. I had a sensor control like that that once it hit a degree temp it would open the circuit and turn on my fan.. The stock temp sensor can be found on the driver side of the engine below the #1 & #3 cylinder.

Does the temp gauge work??

 

Yes, temp works. Fan stays on all the time. Could this be the reason???? Or would the fan not come on at all if this was broken???

 

i doubt it, in order for it to be on all the time off the sensor, the prongs (which i can't really see in the pic if any at all) would have to be jumped from one to the other but in effect, it would probably run while the car is off unless someone took some time to wire it propely to be engaged by the key posistion.. Look under your dash at your fuse panel/trace the wires coming from your fan n determine where they recieve their power.

If you want to control the fan, i suggest getting a toggle switch. They make a 30 amp switch at any autozone/advanced, a 25 amp probably would work too but u would have to use a fusible link (with both switches) to control power so u don't burn up
a. the fan motor
b. the switch cause they melt easy.


If your interested in how i wired my toggle up, PM me. As for that plug, unplug the wires n see what happens, looks like it was just an old relay to control the fan on n off power along with a certain degree sensor is probably wha it is

 

I have a similar setup on my 85 iroc, where there are 3 temperature sensors on the 350 block. The one on the drivers side is for the temperature gauge on the dash. The one on the passenger side is for switching on/off the fan, and as I understand it the third one on the top is for a warning light.

However the one on the top isn't what its supposed to be as it is a variable sensor, not the switch that the warning light would require. I would think that the engine(with sensors) was intended for a vehicle with a computer, and the 84/85 not tpi cars didn't have one.

If you want to find out what type of sensors you have, then try connecting an ohm meter up to the terminals. If its open circuit/shorted then its a switch, but if it has a value of 100ohms to 1kohms then its a variable sensor.

What you need for the cooling fan is a thermostat switch to put in the passenger side of the block, though a manual override switch in the car's interior is useful....

 

I'll SWAG it as the exhaust heat riser control sensor. If it has vacuum ports on it (which it looks like it may) instead of a connector. . . .

RBob.

 

The only two things that go into the t-stat are EFE vacuum temp switch & the canister purge vacuum temp switch. In that position it looks like the EFE (aka heat riser) switch.