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AMEDEE
AMEDEE, CHEVY TECHNICIAN
Category: Chevy
Satisfied Customers: 24806
Experience:  ASE certified tech ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
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Chevrolet Uplander LS: 2007 chevy uplander cooling fan always

Resolved Question:

2007 chevy uplander cooling fan always running
Submitted: 4 years ago.
Category: Chevy
Expert:  AMEDEE replied 4 years ago.
Hello and Welcome to Just Answer. My name is XXXXX XXXXX I will try my best to assist you and your 100% satisfaction is my goal. I have been working on these vehicles for over 10 years so I am very familiar with this system and how they work. However, keep in mind, that I need some solid concrete facts/evidence/clues from you in order to give you a good answer about your vehicle. Please realize that all my answers are based solely on the info that you provide me with.


Is the check engine light on?

Are there any codes in the computer?
Customer: replied 4 years ago.
no engine ligth and no code
Expert:  AMEDEE replied 4 years ago.
Ok.. if there are no codes in the ECM, TCM or BCM, then chances are you just have a bad AC pressure sensor. This is very common. You might be able to get the fan to stop running if you disconnect this switch. The computer will turn on the low speed fan if the Ac pressure sensor signal is not within specs. If the AC is off, the voltage on this pressure sensor with it plugged in should be 1.0 volt or less. Just be sure that the Freon level checks out ok.
Customer: replied 4 years ago.
I already disconect the AC pressure switch but the fan still running on high
Expert:  AMEDEE replied 4 years ago.
Ok.. plug it back in and tell me the voltage reading.. Be sure the key is on when doing this.
Customer: replied 4 years ago.
Gray wire is 5 volts and the org. wire is 2.89 volts ign on
Expert:  AMEDEE replied 4 years ago.
Is this with it plugged in?
Customer: replied 4 years ago.
yes plug in . If unplug the gray has 5 volts and the org. has 0 volt.
Expert:  AMEDEE replied 4 years ago.
Ok.. then the only thing left would be the refrigerant level.
Customer: replied 4 years ago.
The High side is 250 PSI and low side reading was 60 PSI, engine off. Engine has been off for at least 20 minutes. Shouldn't the both equalize?
Expert:  AMEDEE replied 4 years ago.
YEs.. they should. How do you know the AC pressures? DO you have an AC machine?
Customer: replied 4 years ago.
yes i just hooked it up and got all does readings
Expert:  AMEDEE replied 4 years ago.
Ok.. I would start the engine and check the AC pressures. In addition, evacuate and recharge the system and see if that helps.

Let me know!
Customer: replied 4 years ago.
High pressure goes up to 300 PSI and low side to 20 PSI. evacuate or recovered 134a are 20oz and the spec. i 1.43 ibs or 23oz
Expert:  AMEDEE replied 4 years ago.
Do you have rear AC?
Customer: replied 4 years ago.
no
Expert:  AMEDEE replied 4 years ago.
yeah.. you re correct about the specs.. but the AC pressures are WAY off. If you charged it correctly and your AC machine is calibrated correctly, it sounds to me like you just have a restriction in your AC system.
Customer: replied 4 years ago.
i will charge it first and go from there. If the same pressure then i look for restriction. Any clue were could that be. Do I ask to much.
Expert:  AMEDEE replied 4 years ago.
My experience has been either a plugged orifice tube/expansion valve or a plugged condenser.. but it could be anywhere. Check those two first.

No.. you don't ask too many questions.. just please don't forget to hit the green accept button so that I may get credit for helping you.
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