So if you unplug the radiator switch and jump the harness connector there, the fan comes on?
On a side note, you shouldn't be getting that hot at an idle to require the fan's help unless it's vERY hot outside. I'm suspecting your fan clutch is bad and the mechanical fan is therefore not pulling enough air through the radiator when at a stop.
Originally Posted by chris87xj
If you own a Renix Jeep, you'll want to check this out. >
An index to over 25 write-ups can be found in Post #1.
Elec fan is supposed to kick on at 210* or when the A/C is on. Bad relay is a common problem, but if it's working with the A/C then it's not the relay.
As for the fan clutch, if you can stop the mechanical fan when the motors running then it needs to be replaced. Very easy to do, just undo the nuts or bolts (forget which) on it, slide the clutch and fan off, replace with the new one and bolt it back up. I'd suggest replacing it with a ZJ fan clutch over the stock one.
Prior to replacing the switch I used a wire to jump the connection where the switch plugs in and the fan worked fine. But replacing the old switch with a new one did not correct it.
Cruiser you recommend a stock clutch then?
Mechanical clutch didn't help. The overheating issue was ultimately caused by a radiator reservoir not holding pressure. It had been replaced within 6 months but on the new one the threads couldn't hold the cap tight. New unit with new cap cured overheat issue.
Then yesterday with an idling vehicle dragging junk around my place the fan started working without the A/C on. Maybe the leaky reservoir somehow kept the temp below the threshold. Gauge read just a touch over 210 when it kicked on. All is good in the cooling department now.