Ask a Mechanic Online and Get Answers to Your Car Questions
HiCustomer Thank you for asking your question on Just Answer.
Are you saying that you have TWO problems1 - AC compressor does not run unless jumpered to power and2 - Mode control doors (which switch between dash vents and floor vents) will only blow out the floor vents?
Also, is the a "manual" or "Automatic" AC system (automatic is where you have a "set temperature" - usually a digital display)
Take Care, Greg A.
So the blower blows air through the dash vents, floor, or both depending on the mode switch - Right?
Is the AC compressor coming on at all?
I assume you want to get the AC going first?
Has the refrigerant charge been checked recently? I know you jumped directly to the compressor, but if it is just slightly low, the pressure sensor will keep it from coming on.
Here is a diagram related to the AC compressor control. You will notice there is a reference to the ECC (Electronic Climate Control) module. I will take a look at that.
In the mean time, I would suggest that possibly the fuse(s) or relays may be suspect (upper left of diagram). If those are working OK, I think we will be looking at the ECC.
Let me know if you discover anything while I am looking up the ECC.
Oops - I clicked on the automatic system. You can ignore that last answer.
Give me a couple of minutes to get it the right one.
What Engine do you have (2.2 or 4.3 liter)
I will take a look, but I think that was on the "automatic" AC system.
By the way, is this a 2 orXXXXX It might make a difference.
Also, what is the engine size?
What engine size? (2.2 liter or 4.3 liter)
OK. I don't think you have automatic AC (from what you have said) but here is the location:
ECC Module Location (with Automatic AC): The IP harness center of the IP, below the radio.
OK - I think we are getting closer.
Here is the diagram for AC Compressor control for your vehicle. I will get you a diagram for the location of the VCM (Vehicle Control Module), if you need it. It is under the hood. and has 4 connectors on it.
Here is the location of the VCM and the connectors. Look for loose connections.
I would also try jumpering the compressor relay control to ground and see if the compressor comes on. That would verify that everything is working (fuse, relay, etc.).
If that makes it work, we will have to go backwards towards the switches inside the cabin.
Sometimes the diagrams in the manual are "generic" and will not exactly match what you have. I have also found mistakes in the manuals some times.
What I show is what I have for the 99 Jimmy Manual AC 4.3 literXXXXX
I'm glad you found it. Congratulations!
Did I help enough for you to Accept an answer?