yesterday I had my battery cables replaced, belt replaced and the bank 1 and 2 O2 sensors replaced. I also replaced the battery this past week. I also had my mechanic test the AC- had a leak so need to fix that. leaving the shop and driving home I noticed it would randomly rev from 600 to 1000 whenever I came to a stop, even sitting at a standstill it would rev from 600 to 1000/1100. I get home and my its from my AC clutch engaging. im not sure why its engaging as I don't have my AC on, I have the defroster on but on the heat setting. any idea why its doing this?


ive only owned this jeep since nov. so I have had no need for the AC, but I am planning on getting the system operational and leakfree. just wondering why its engaging and causing such a spike in my rpms when its not even turned on.

 

My understanding is that the a/c compressor comes on in the defrost mode to eliminate any moisture in the vehicle helping to eliminate interior fogging. Having said that I haven't noticed my rpm's varying that much.

 

im guessing my belt was prob worn out to the point I never felt it or noticed it engaging- but man you can now...