Second sensor on thermostat housing?

I think I'd expect the fan sensor that was used on the electric fan used on the Wrangler 2.4L engine that came along in 2003 to be your best bet. Mopar p/n 56027873.
 
Okay, maybe I’m missing something. How does that relate to this? I need to track down what this sensor is so that I can replace it.

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In this pic, it looks like your wire should have been (or was) connected to the lower sensor terminal. Maybe that sensor, when it hits the correct temp, just closes the connection between the two terminals. And not to ground. Maybe that upper terminal in your sensor should be wired to positive (fused, of course), ground or ????
Maybe that is why you’re getting the code. Pull the sensor, throw it in boiling water and do an ohms check.
 
Cool, yeah. Been looking at these. Still trying to find one that received the same lead-wire connecion. Will keep lookin.

Thx all.

Those will plug in, remove the metal terminal from the electrical terminal. Then the new sensor.
 
interesting. I’m getting p1281 “check ECT” error but Ive replaced the sensor (which was clean), installed a new thermostat (also clean but see note) and I’m still getting the error.

Wonder if that fan sensor/connector lead might be causing the problem. The lead literally snaps on to that sensor port. And not sure if its visible but the black insulation is broken. I’d like to fix or replace but the problem is…i dont know what it is. previous owner installed. Ugh.


side note: When I pulled the old thermostat, it was a 165 degree model. I know that’s a no-no, but Im wondering if it could/should work in tandem with the aftermarket aluminum radiator and electric fan setup.

P1281 is engine not reaching operating temperature. Put the 195 thermostat in and a 221 fan temp switch. This should take care of it.
 
P1281 is engine not reaching operating temperature. Put the 195 thermostat in and a 221 fan temp switch. This should take care of it.
The 195 degree thermostat alone will fix that problem. The fan temperature switch only controls the fan, the PCM doesn't know it's there.
 
so....more questions...

Are a "fan sending unit" and "cooling fan thermostat sensor switch" the same thing? or different?
 
so....more questions...

Are a "fan sending unit" and "cooling fan thermostat sensor switch" the same thing? or different?

Not really the right description should be a temp switch or cooling fan switch. It yes those should work. If you want send me a link I’ll look at it.
 
Interesting. So, if the standard engine operating temp is 210, then is the mechanical fan running most of the time? Or is the air in that area that much lower than the engine temp? What sensor is measuring that air temp?
 
Interesting. So if, standard enging operating temp is 210, then is the mechanical fan running most of the time? Or is the air in that area that much lower that engine temp? What sensor is measuring that temp?
There is a bimetal spring on the front of the fan clutch

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Put a piece of cardboard or a blanket over the front of the Jeep you should be able to hear the clutch lock up. The fan will get loud and airflow will increase.

I dont have the oem fan, which why I was asking. I have an electric fan which relies on a completely different method of gauging temp to determine when to turn on.