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Ask sprinkles08 Your Own Question
sprinkles08, ASE Certified Technician
Category: Jeep
Satisfied Customers: 23112
Experience:  Chrysler/Dodge/Jeep Master Certified, ASE Master and Advanced Certified, Trans and Hybrid Specialist
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The idle goes up and down by 500 RPM wiyh A/C on at stop in

Customer Question

the idle goes up and down by 500 RPM wiyh A/C on at stop in gear brakes on
JA: How many miles are on the car? What size is the engine?
Customer: had it in to Chrysler they couldn't find anything, no codes
JA: What is the model/year of your Jeep?
Customer: 2014 compass
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: nothing, I'm trying spark plugstoday
JA: Anything else you think the mechanic should know?
Customer: I've tried injector cleaner
Submitted: 1 year ago.
Category: Jeep
Expert:  sprinkles08 replied 1 year ago.

Hello and welcome to JustAnswer!

To have a fluctuation that large only with the a/c on I would first suspect the cooling fan isn't running at that time. If it isn't then the compressor will put a large load on the engine due to the high pressures in the system and it will cause what you're describing.

When the problem is happening can you see if the cooling fan is running?