I have a Climate Control type HVAC system in my 2003 Envoy. The AC and Heater and all the vents switch from floor to front to defrost as expected. The driver and passenger side temperature control knobs work normal also. It is just that the blower runs irratically, at different speeds on auto and the manual speed control light indicators go up and down in the display panel, but does not control the motor speed. I suspect it might be the Blower Motor Control Module. Is that a good deduction? And if it is, where is the Module located. If it is something else, please advise me. Thanks
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What A/C problem did you have , original complaint for taking to the dealer ? Does the blower motor blow air out of the vents , when switching from floor to center vent to defrost does air change direction ? What make model an year is your vehicle . Does your vehicle have manual or automatic climate control . Were there any codes stored in the control panel ? Mode door or temperature control problem ? Do you here any clicking behind the dash ?
I am experiencing the same problem. I've had two different diagnoses:
1) Blower Motor Control Module/Resistor (under $40)
Dorman Part # 973442
2) AC and Heater Control Switch (Reman. Part: $234 + Core charge of $222.)
DORMAN Part # 599030
(Prices current from RockAuto.com.)
In addition to the recent blower problem, 5 years ago I had the A/C blowing out the floor/defrost vents only, too; but with no vacuum leaks. I was told then I needed the AC/Heater Control Switch; but instead I made it a "manual" automatic climate control. I disconnecting the vacuum connector plug from the control unit and used the male end to make the connections. It was much easier on my pocket book and still works today.
The connections I found on my 2003 Grand Marquis:
Blue: Panel door
White: Air inlet door
Yellow: Floor/Defrost door
Red: Floor door
The Fix: I used a vacuum hose directly from Black to Blue and White. This required a short piece of vacuum hose with one T connection. The temp control still works including the fan speed control (until now). I live in Texas and it doesn't get too cold. But occasionally I connected Black to Yellow directly to get me thru those real bad cold spells. Bottom Line: Not sure what I going to do but leaning towards replacing the Control Switch and the vacuum connector plug. Especially, since the price of the switch is more reasonable today. A 50% savings from 5 years ago.
Hi, viewer. I guess what you mean is that your rear a/c system is not blowing air, even if rear blower set to max speed, you cant feel or hear the rear blower motor spinning. One of the most common issues for the rear a/c on gmc envoy is an inoperative auxilliary blower control module or resistor.Sad to say this component isnt easy to access. Standard servce procedures require the removal of the rear quartertrim panel and garnishes, removing the whole auxiliary hvac module. But once you have removed the quartertrim panel and the rear hvac module now uncovered, you can begin to isolate effectively every other possible cause of failure. So goodluck, then.
REMOVE HEATER BLOWER MOTOR HOT WIRE BLOWER MOTOR IT.IF IT WORKS.YOUR AC AND HEATER CONTROL SWITCH IS FAULTY.CHECK HVAC FUSES AND CHECK BLOWER MOTOR RELAY.IF BLOWER MOTOR DONT WORK WHEN HOT WIRE REPLACE IT.IF ALL CHECK OUT GOOD.HAVE DEALERSHIP DO A DIAGNOSTIC TEST ON YOUR CLIMATE CONTROL SYSTEM.
MAKE SURE BLOWER MOTOR OPERATING IF NOT CHECK FUSE AND RELAY.ALSO CHECK HVAC FUSE THIS CONTROL HEATER + AC CONTROL SWITCH AND MODE SELECTION FOR OPENING AND CLOSING HEATER DOOR OR HEATER CONTROL VALVE AND AC+ DEFROST AIR DOOR.IF BLOWER AND HVAC FUSE OKAY.IF YOU HAVE MANUAL HEAT CONTROL MAKE SURE MODE SWITCH IS RECEIVING VACUUM. YOU HAVE TO REMOVE HEATER CONTROL SWITCH AND CHECK TO SEE IF GETTING VACUUM GETTING TO SWITCH LOOK FOR BROKE DISCONNECTED VACUUM LINES IN THE DASH AREA.IF YOU HAVE CLIMATE CONTROL.YOU COULD HAVE A FAULTY ELECTRICAL HEAT DOOR ACTUATOR.SOME CLIMATE CONTROL CARS HAS THE CLIMATE CONTROL PROGRAMMER HAS TO BE REPROGRAM BEFORE THE HEATER AND AC WILL WORK AGAIN.YOU NEED A DEALERSHIP SCANNER TO CHECK IT OUT.BUT IF YOU HAVE MANUAL CONTROL CHECK TO SEE IF YOU GETTING VACUUM.IF YOU GETTING VACUUM AT HEATER DOOR VACUUM ACTUATOR OR HEATER CONTROL VALVE EITHER ONE OF THOSE COMPONENTS COULD BE FAULTY.WARNING YOUR VECHICLE HAS AIRBAGS YOU HAVE TO DISARM THEM BY REMOVING FUSES WAIT 20 MINUTES BEFORE WORKING ON DASH AREA.YOU HAVE TO CRANK CAR UP TO CHECK TO SEE IF YOUR HVAC GETTING VACUUM.
first check to see if you have power going to the actuators when you switch the switch to it location if no power replace controller if you have power and no movement from actuators replace actuator. if actuators move remove hvac box and check for broken blend doors.
Need to check to see if the blower motor is running.If it is,but not threw the vents,most likely a vent door actuator motor.The actuator motor in this case would be bad,it is hard to get to,unless you are mechanically inclined,You can do it your self.If the blower motor is bad,just replace it.Check fuses first,and the blower relay.If I can help,let me know.
sounds like you have two problems, if there is no air from front then you need to ck power to your blower motor, if no power you need to ck your blower resistor and connector, second if no cool air from rear your compressor may not be engaging, make sure you ck your fuse for the front hvac system.
ok could be one of 3 things. 1 you may be out of freon. (proly spelt that wrong) 2. compresser could be bad. 3 the clutch on your compresser might not be engaging. when trucks running turn ac on and see if the front of your compresser spins or not. if it does clutch is good. but it could be that your compresser is still bad. either way i recomend you go for freon and start there. when they fill it they will tell you for sure wether or not your compresser is bad.