Might sound like a small thing but my jeep gets no heat to the extent that it doesn't reach operation temp. Checked the code behind the CEL and I got P1491(Radiator Fan Relay). The odd thing is both mechanical and electrical fans run from Start. Checked fuses though they looked fine I still replaced them and still nothing. Only other odd thing is that air compressor turns on and off with A/C on High.... any ideas?

 

http://www.justanswer.com/jeep/1v3d9...ced-relay.html

 

in oreder to do that i would need an advance obd scanner tool. i only have a cheap code reader. Any other suggestions?

 

make friends with a parts/tech guy at the local dealership

 

With a P1491 you may want to just replace the electric radiator fan relay in the PDC. It sounds like the power contacts in the relay are stuck closed. Not unusual.

The air compressor will cycle with AC or defrost selected. Read post #42 in this thread to learn how your AC switching system works.

https://www.cherokeeforum.com/f2/gre...e-6558/index3/

 

What is that? (PDC) Do you mean PCM?

 

Power Distribution Center: the underhood ' fuse and relay box' ...near inner fender wall.

 

Thank you CCKen and cf for sharing your knowledge

 

Here's the 2K and 2K1 PDC relay arrangement. You may not have all the relays, depending upon your vehicle options.

 

Hey! Roler's got pics.

 

lol, naaah....Google got pics
(not home, so no access to my own ' extensive and comprehensive' collection of pics)

 

Thank you for all the pics and knowledge CKen

 

Just an update to close this book on this chapter. I was able to correct the issue of the P1491 code. I followed CCKen's advice and purchased a new relay from Advance. Used an online code got it for about $6. Took the old to compared to the new...they matched. Went home and put the new relay in. Took my code scanner and erased the code and turned on the engine and boom


no boom. but electric fan is working properly now. Now to check that a/c compressor but i'll start a new thread for that

 

Glad it's fixed.

Thanks for the follow up (Roler will be happy).

 

Very. Closure is good. Thanks.

For future reference: switching a suspected bad relay with a known good one, can be helpfull to verify it being the relay thats bad.
Reminds me of that time my e-fan relay going pear shaped(would intermittently stay closed): e-fan would continue running after engine shut down. Switching it with the ASD would leave me with the XJ continue to run for 2 seconds after the key was already out....funky.