No A/C in Arizona @#$%&

[whoozey1953]

Replaced electric fan on 2001 XJ 4.0, but the connectors weren't the same. I went back to the stealership with the fan, and they said that was the only kind of connector they came with. I hate the stealership! I went back and took the plug off the old fan and spliced it onto the new fan using butt connectors. Fired up the Jeep, turned on the A/C, and the electric fan never came on. I unplugged and replugged the connector from the T-stat housing sensor while it was running, the fan still wouldn't come on. I turned off the motor, started it back up, the MIL light is on in the dash, the A/C doesnt work now! WTF?!? The fuses are good. Anybody got any ideas? By the way, it was 117 @&#%$ degrees here yesterday! TIA

 

[rixXJphx]

Couple thoughts:

1. I *think* the fan won't come on until the temperature reaches something like 210*+F.
2. I *think* the temp sensor you unplugged while the engine was running sends a signal to the 'puter, and now you've confused it.
The 'puter puts itself into a default 'run-safe' rich mode when it's confused. I *think* one of the default settings is to shut-off the AC since it's not a critical system ('cept in Phx ).

Solution:
Drive the vehicle about 5 minutes at operating temperature. The 'puter is continually self-diagnosing.
Once it understands that all systems are again 'nominal', it will exit the default mode and all will be well again.

Course, my XJ is an old carb'd model and I've never experienced an FI Jeep.
But the above is based on my understanding of newer cars I've owned and worked on.

Good luck.
-Rick

 

[whoozey1953]

I already have driven it an hour, disconnected the negative on the battery and reinstalled it trying to clear the code, turned the key on and off 3X, it is still there. You can appreciate my discomfort, being from the same hubs-of-hell Valley of the Sun! I hate to say it, but I guess I will have to go to Earnhardt Jeep tomorrow and bring my jar of sandy vaseline with me.

 

[Kejtar]

the fun should be doing a weird on/off cycle while the ac is on..... if it ever worked for you, you know what I mean....

Kejtar

 

[rixXJphx]

Another thought:

Relative to splicing in the fan with the wrong connector: Any possibility you reversed the wires?
Reversed DC power *should* only result in a backward fan rotation, but maybe it also affects the 'puter.

 

[whoozey1953]

Blue to blue, black to black. Checked on straight 12V power to make sure it worked. It is at the stealership now, I just had the interior detailed and I don't want want white crusty sweat stains all over the cloth seat. $85 just to hook it up! Whatta racket!

 

[Judd W. VA]

Okay... had to replace the fan on an XJ so new?? What was up with that?? Sure the old one was bad?? Sounds like there is something else going on here and the old fan was not bad to begin with. Now the dealer says the fan they did supply that wasn't right is the only one available for that?? ......is also stupid. Sounds to me like the dealer has only added complications to the original problem(s).

The computer sends a signal to a relay in the PDC that in turn runs the fan. Sounds like that relay is messed up shorting that signal from the computer. I have had sticking-on problems with that relay on my '98, so that leads me to believe it is a problem prone relay. All dealers aren't bad, just 1/2 of them!!

 

[whoozey1953]

It has 61K miles on it, I use it for my sales/engineering job. The old fan still worked, it just had a bad vibration when running, the antenna looked like a sidewinder rattlesnake crawling thru the sand when it was idling. All is fixed now, taking the sensor wire off of the T-stat housing while the engine was running caused a code to the computer making it shut down unnecessary (not to me) items like the A/C. Cost me $125 bones, a lesson learned. Thanks to all for the input, this is a fantastic site.