Testing the fan clutch

[Mike W.]

Anything special about testing the fan clutch on an 03 QX4? Technique I'm used to is get it good and hot, then try to stop the fan with a newspaper. If you can it's bad.

[Mike W.]

As a followup. I tried to get it good and hot, although not as warm as I was targeting. The A/C cut out (hmmm, I wonder what causes that?) and I could still stop the fan with a newspaper, but not easily. I'm guessing it's weak but not gone. I'd much rather one or the other.

[Blindaviator]

As a followup. I tried to get it good and hot, although not as warm as I was targeting. The A/C cut out (hmmm, I wonder what causes that?) and I could still stop the fan with a newspaper, but not easily. I'm guessing it's weak but not gone. I'd much rather one or the other.

After my engine swap a few weeks ago I was recharging the A/C with my brother... What we noticed was while it was sitting still idling the fan wasn't pulling enough cool air across the coils in front and it would cause the high pressure side of the A/C to exceed the safe high pressure causing the compressor to cut out... Once the car was moving it wouldn't do this...

[Mike W.]

As a followup. I tried to get it good and hot, although not as warm as I was targeting. The A/C cut out (hmmm, I wonder what causes that?) and I could still stop the fan with a newspaper, but not easily. I'm guessing it's weak but not gone. I'd much rather one or the other.

After my engine swap a few weeks ago I was recharging the A/C with my brother... What we noticed was while it was sitting still idling the fan wasn't pulling enough cool air across the coils in front and it would cause the high pressure side of the A/C to exceed the safe high pressure causing the compressor to cut out... Once the car was moving it wouldn't do this...

I am familiar with high pressure cut outs and that would make sense given that I had cardboard in there. However I also experienced it on vacation in a couple of instances where I was going up a very steep dirt road and the engine got hot. Not overheated, but hot. It would make sense to shut off the A/C to reduce thermal load under certain conditions, but I hadn't heard of it. Nor have I looked at the wiring diagram. An auxiliary fan is in it's future.