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Engine running hot question, but not overheating?

jt29

NAXJA Forum User
Location
So. Cal.
  • At what temperature should the electric fan come on with the a/c off
  • I’m sure there is a temperature switch for the eclectic fan were is it located and could I install a lower temp switch so the fan will come on earlier?
3. Would an exhaust leak cause the engine to run warm due to built up back pressure on the motor
 
I think the electric fan kicks on at 210, but it could be lower (190-210).

The temp sending unit is in the thermstat housing on the upper right side.

Does the fan come on when your AC is turned on?

Exhaust leak = no
 
the temperature is 190 degrees. the location of the switch differs in models, in mine '89 it is in the motor side of the radiator on the drivers side.
 
2lazy2p said:
the temperature is 190 degrees. the location of the switch differs in models, in mine '89 it is in the motor side of the radiator on the drivers side.

Thanks! I started with that and then second guessed myself.
 
Last edited:
Found this in a search...

I have a 1999 XJ, and I'm pretty sure I've seen the CTS sending unit coming out on the drivers side of the thermostat housing. The wire itself is covered with a plastic wire loom. This is a whole lot different than my '89 XJ, where it comes off the back of the engine block near the valve cover...

What year XJ do you have?
 
I have a 94 XJ. The fan comes on when I turn the a/c on. But I do not hear it when the temp hits around 210-225 with the a/c off.
 
jt29 said:
I have a 94 XJ. The fan comes on when I turn the a/c on. But I do not hear it when the temp hits around 210-225 with the a/c off.

Replace the temp sending unit. Its on your thermostat stat housing pointing out of the upper driver side. I recently had the same problem. Went thru all my relays and they were fine. Temp Sending unit looked okay and wasn't but a couple years old, but I replaced it and the fan started working.
 
Bored400 said:
You could also just wire a bypass switch and call it fixed.

Not sure on the earlier year XJs, but on the 97+; the fan motor is constant hot and switched ground....
I installed a 12V relay that allows for normal use of the fan when the A/C is on, but can switch in additional ground for running the fan in bypass to cool the engine while off roading if the A/C is off....
 
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