Electric fan question

[ltd02]

Did a search but couldn't find the answer to this one out there on the world wide internet web thingy.

I was reinstalling my HD clutch fan this afternoon and after firing the libby up to make sure it was okay I decided to check my AC charge. It was fine but I noticed that my factory original efan came on immediately but only for a bit and as the AC comp cycled it slowly stopped. AC was still on at the time. I always assumed it stayed on as long as the AC was on. Anyone know if this is correct?

I tried to get the temp up to see if it would work at that point but between it being cool out (low 60s) and the HD fan working enough I could only get the coolant up to about 96C. I may take another try in an hour or so.

 

[uss2defiant]

The e-rad fan only comes on at certain conditions.

OPERATION
The electric radiator cooling fan is controlled by the Powertrain Control Module (PCM) through the radiator cooling fan relay. The PCM regulates fan operation based on input from the engine coolant temperature sensor, battery temperature sensor,air
conditioning select switch and vehicle speed. The fan is not energized during engine cranking regardless of the electrical input from the temperature sensors and ,air conditioning switch. However, if engine operation conditions warrant fan engagement, the fan will run once engine starts.

Vehicles Equipped with AC:
In addition to using coolant temperature and battery temperature sensor to control cooling fan operation, the cooling fan will also be engaged when the ,air conditioning system is activated. The relay is also energized when, air conditioning is selected and coolant temperature is above 95° C ( 203° F), or , air conditioning is selected and battery temperature sensor is above 41° C (106°F). It will then de-energize when , air conditioning is selected and coolant temperature is below 92° C (198° F), or , air conditioning is selected and battery temperature is below 38° C (100° F).

http://www.jeepkj.com/forum/f196/what-did-you-do-your-jeep-today-50782/index656.html#post655067

Here's a google-fu tip:
type in your keywords followed by site:www.jeepkj.com

 

[ltd02]

Wow thanks! That pretty much nails it. Sounds like it is operating correctly as per the bolded part of your post. I was using a bluetooth scanner to watch my coolant temp and was mid 90sC. Doubt it was really that accurate. Also doubt the battery temp would have been anywhere near 100F too. I was always assuming it came on and stayed on when the AC was selected no matter what. Still need to replace my crappy shroud. Looks like the hardware is about to fail.

I appreciate the search tip too!

 

[uss2defiant]

oh also,
I'm planning to trim my HD shroud some time soon, going off what twobobskj did with his so the shrouding can be removed without removing the clutch fan.

I think if you haven't done that yet it might be a good idea.

 

[CzarKJ]

oh.
I'm planning to trim my HD shroud some time soon, going off what twobobskj did with his so the shrouding can be removed without removing the clutch fan.

DO IT! Makes it sooo much easier. I just loosen the bolts on the radiator crossmember and the fan pops right out with the clutch going right through the cutout.

 

[ltd02]

I did that about a month after I bought my KJ. Dremel and you can't even tell it was modded. :happy160:

I just ordered a new one from Avondale and I'll trim it as soon as it comes out of the box.

Thanks

 

[uss2defiant]

wait? you ordered a new shroud?
thought you just needed a new electric radiator fan?

 

[ltd02]

No I had the fan but when I went to install it in my original shroud I realized the shroud hardware (bolts and clips) were just completely rusted. I had posted that in the "What have you done to your KJ today" section. I just put the old combo back in as it still works. I'll install the new fan in the new shroud when it arrives, put that all in and be good to go. Sorry about the confusion, I'm in the process of doing three things at once but none of them well.

I'm actually waiting for the clips to give and have the efan fall out of the shroud as I'm driving.