I'm having two issues and I can't figure out if they are related. No CEL, but the jeep occasional runs hot in traffic (halfway between 210 and the next mark) and sometimes experiences a heat soak

Electric fan does not come on at temp or with the A/C system selected on. If I disconnect the coolant temperature sensor, it comes right on. Plug it back in, nothing.

A/C System not working, compressor doesn't kick on. It used to, but it just blows hot. Working on diagnosing this, I suspect a leaky seal somewhere due to the jeep sitting for a while before I bought it (maybe 2+ years).

Could the electric fan issue be caused by the A/C system interfering at the ECU level? Is there a chance I have an ECU problem? Any thoughts are appreciated.

 

Believe it or not, you only have 1 problem...the fan should kick on somewhere around 220 give or take..thats very close to the hash mark past 210...further up the gauge than you would expect so you haven't reached fan on temp yet. If you have an obd2 reader select coolant temp and see what the computer thinks the temp is. Your main issue is the computer will not engage the fan unless there is power to the ac clutch. Since you have lost "freon" the low pressure switch has disabled power to the clutch killing the fan on circuit to the ecu. I will go thru the prints later to refamiliarize but a quick check might be to either jumpr the 2 pins in the low pressure connector and pull the clutch relay out . Turn on any ac mode..see if it works. ( the fan). Or you might have to disconnect the low pressure switch and pull clutch relay..i will check tonight. If you leave the clutch relay in and trick the low pressure switch the ac will try and engage and you might damage the compressor if no freon

 

Thank you! I managed to jump the pins in the LP connector and the clutch and AC compressor kicked on, along with the electric fan.

I took it to a local AC shop and they threw a charge on it with some dye, will be returning in a few days to a week in the event of a leak. For now, it seems she is holding pressure, and the fan operates as it should.

In my research on the electric fan and heat soaking, it seems some people have added a second "timer relay" connected to a momentary button on the dash and spliced the connection into the fan side connection, to get the fan to run for 1-3 minutes after actuation. Wired "hot" it could be a post-shutdown fan timer to stop the soak. That may be something I look into doing in the future.