2nd Gen Non-Engine/Transmission A/C runs with heater

[scotty-u]

When ever I turn the fan switch to the right (non A/C) the A/C compressor cycles 2-3 seconds on, 8 seconds off. Fan speed makes no difference, nor does rpm. Any suggestions?

 

[DavidGardner]

I have a 12 valve and whenever I turn on the defrost or defrosat combo my aircompressor comes on. TYhe same as if I was running the air conditioner. I also have a 99 Jeep Cherokey That does the same thing. I was told by the dealer that this is normal. When ever the defrost is selected it turns on the air conditioning system to dry the air that is going too the windsheild. Hope this helps. Sounds like it is normal.



Dave Gardner

 

[RMachida]

I have a 12 valve and whenever I turn on the defrost or defrosat combo my aircompressor comes on. TYhe same as if I was running the air conditioner. I also have a 99 Jeep Cherokey That does the same thing. I was told by the dealer that this is normal. When ever the defrost is selected it turns on the air conditioning system to dry the air that is going too the windsheild. Hope this helps. Sounds like it is normal.



Dave Gardner

Cold air can't hold as much moisture so it gets cooled by the A/C to remove moisture before being heated back up and blown on the windshield. This helps minimize the glass from fogging up.

 

[ToolManTimTaylor]

Yep totally normal. It's when it doesn't ... . that is when ya start to :{

 

[litespeed]

Yea,



Normal operation..... Why cant they give us an A/C compressor switch??? Just about every German and Jap. car I have owned gives you the option of turning off the compressor with a switch!! Including the current Volvo we own... .



A bunch of older Chevys I owned were like this too (like the Dodge). You know... ... ... The ones with the sliding controls that always broke.....



They must think we are stupid or something?



If I want to defog... . I'll decide... ...



AJ

 

[scotty-u]

Thanks to all for your comments. Knowing this is normal puts my wallet at ease. Don't know where my signature is... so this is it: 1994 3500 4x4, 5 speed, muffler stored in garage, 256,000+ miles and still going strong.

 

[mmhjs]

I've taking out the fuse for the compressor for now any ways. I think my truck gets a mile or two better fuel economy Oo.

 

[biggy238]

It should only run on Defrost setting though... . something's up if it runs in other vent positions.



It is running the Condensor which condences the moisture in the air charge, thus preventing that moisture from condencing on your cold windshield.



I freaked out about mine too because it was coupled with a huge electrical problem I had.