Engine Temp gauge quit. Need Help!

[jkufen]

Hey I just noticed today that my temp gauge in the truck never moved even after the 150 miles I drove today. I am assuming I disconnected the wiring in the engine when I was washing off the engine. I went mudding last week and I was spraying out the engine bay and I guess the pressure from the house must have pulled the wire loose. Can anyone tell me where the sensor is located? I have no idea where it is in the engine. Thanks!

 

[85_bronco24x4]

The sensor for the temp gauge is the single wire sensor screwed into the intake near the thermostat housing, IIRC. At lease it is on my 89. At any rate, look around the T-stat housing and you will see a single wire sensor. That's the one for the temp gauge.

 

[RonD]

Yes, the single wire sensor is for the dash gauge, there is also a 2 wire coolant temp sensor(ECT) for the Engine computer.

You can test the 1 wire sensor setup by unplugging the wire and then with key on ground that wire, gauge should go to full Hot, disconnect ground and gauge should drop to cold.
That means wire and gauge are good.

The gauge sensor is just a resistor type sensor that loses resistance as it is heated up.

And just as a "heads up", if you ever need to replace a 1 wire sensor never use teflon tape or anything else that covers all the threads, the threads are the ground connection for a 1 wire sensor.
Most 1 wire sensors come with sealant tape already added on the upper threads and the lower threads are left bare metal to provide a good ground.

 

[jkufen]

Hey if anyone can snap a photo of the area id appreciate it. I just took apart my throttle body and my intake to clean it and i might have snagged it loose. Thanks!

 

[kimcrwbr1]

Follow the upper radiator hose to the thermostat housing. there should be two one with two wires and the other with one wire looks like a small brass stud you just press the 90 degree wire connector onto it.

 

[kimcrwbr1]

http://www.ebay.com/itm/New-Classic...Parts_Accessories&hash=item2ec413c43d&vxp=mtr
looks like this