Electric Fan only coming on with A/C

[SBpunk]

So my motor has been running hot since the rebuild and trying to figure out why while I wait for parts and things to come in. Cooler day like today its been running around 230 while idling at a stop light. She's almost always just a tad over 210. Put in a ZJ fan clutch just because I had one laying around from a project a few years back. Didn't seem to help much. While I was messing around under the hood I noticed my electric fan wasn't coming on at the higher temps. I read somewhere awhile back that you can check the motor on the fan by turning the A/C on. Once it was on the fan started spinning. Is there a relay or something besides the temp sensor (new) that I can check to see whats going on?

[SBpunk]

OK so let her idle in the driveway outside temp is 81 and she sat where the picture is. After cleaning up the wheels I noticed the fan clicked on checked inside and she was sitting at the tick right before the red.... Guess when I got my motor rebuilt they put in a inop water pump. Kinda pisses me off considering it ran at 190 all day long before.

[Dzimm]

OK so let her idle in the driveway outside temp is 81 and she sat where the picture is. After cleaning up the wheels I noticed the fan clicked on checked inside and she was sitting at the tick right before the red.... Guess when I got my motor rebuilt they put in a inop water pump. Kinda pisses me off considering it ran at 190 all day long before.

How long ago was the rebuild? May still be under warranty.

[SBpunk]

330 miles lol

[Dzimm]

330 miles lol

I'd check with the rebuilder. It should still be under their warranty or at the very least under the water pump manufacturer warranty.

[johnj92131]

On my 91, the electric fan is supposed to run under 1 of 2 conditions:  1) When the a/c is turned on.  2) When engine temperature is over 210 (?, from memory).  The wire to your temp sensor to the fan may just not be plugged in correctly.  Or your temp sensor is bad.  (Wouldn't that be a simple thing).

 

Hot at idle indicates a bigger problem.  Some thoughts,  Bad Temperature Sensor?   Air in system.  Water pump runs in wrong direction, Pinched or collapsed coolant line.  No coolant in heater.  

The factory service manual has a whole page of reasons for this issue.

 

Take it back to where you got the work done!  But BE NICE about it!  The people at the shop are human too.  Stuff happens, right?

[SBpunk]

I'm always nice until people give me a reason not to be. He's a decent guy but the quality has been lacking. It's about 70 miles from me so less of an issue if I just throw in a new pump. Hopefully that fixes it. Need to find a lower radiator hose with a spring in it. Plus it'll give me a chance to do a proper burb on the system.

[HOrnbrod]

If all is well, the aux fan does come on with the A/C or when the temp sensor in the thermostat housing senses an engine temperature of 215-218 degrees. This is the factory spec. Maybe my 91 did that when it was new, but it's never done that since I've owned it. It comes on at around 230* indicated on the temp gauge. I've tried new sensors to knock it down a bit and it doesn't help.

 

Since I've been running two electric fans for years now and the original aux fan is my backup, I wanted a means to turn it on manually in case my primary electric fan that replaced the mechanical fan went belly up. I wired the aux fan to a dash switch that overrides the sensor and applies a ground to the ECU pin that controls the aux fan. This turns the aux fan on if I need it like when stuck in summer traffic on 100* days. It's easy to do and good insurance. Let me know f you would like a wiring diagram. It works well when/if you need it.

[omega_rugal]

burp the system, vene with everything brand new air in the system is like if you hand no cooling system at all