Ac problem ...need help

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Recently my ac stopped blowing air and i checked all fuses related to ac system, i replaced the blower motor resistor and replaced both blower motors front and rear ... i even swapped out the ac control module and still not blowing any air .... i check the compressor and it engages and disengages like normal .... at a loss at this moment and help or advice on what else could be the problem will be greatly appreciated....thank u in advance
 

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Post up your make, model, and year so we know what we're looking at. AUTO HVAC or manual?

Rigs with the AUTO HVAC control (and probably the others) have two fuses for the front blower motor, which I am guessing is not operating at all. Did you have voltage at the blower motor resistor? Test the blower motors directly with a 12v source? (2000-2002 underhood fusebox is different from the 2003-2006.)
 
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hawaiiantahoe808
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Post up your make, model, and year so we know what we're looking at. AUTO HVAC or manual?

Rigs with the AUTO HVAC control (and probably the others) have two fuses for the front blower motor, which I am guessing is not operating at all. Did you have voltage at the blower motor resistor? Test the blower motors directly with a 12v source? (2000-2002 underhood fusebox is different from the 2003-2006.)

So sorry i forgot to put that info in my post ... i have a 2005 Chevrolet Suburban 1500 and i have the manual hvac control
 

OR VietVet

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When you say "replaced the a/c control module" are you talking about the control head/board in the dash that controls the functions?
 
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When you say "replaced the a/c control module" are you talking about the control head/board in the dash that controls the functions?

Yes i had 2 extra ones laying around ... i recently switched it out for one that i had upgraded with leds and i thought that it might have went bad so i put the original one that was in there back in and nothing changed
 

rockola1971

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Im just not seeing anything in common with the front and the rear yet. The blowers themselves have independent fuses but check those anyway. I sure hope you know how to use a voltmeter. I would start with the front blower and check for 12v at blower module speed control (that module in your air duct left of the front blower). Should be 1-12v on Purple/White and then also the Red wire will have 12v. Make sure blower switch is set to max or you wont get a correct reading on Purple/White wire. If zero on Purple/White then check HVAC/ECAS 10A fuse first. If good fuse then check Purple/White wire coming out of HVAC control module which is what feeds the Purple/White to the Speed Control (this is your actual speed control wire and will have a variable voltage depending on what blower switch is set to for blower speed). This will be 1-12v if good. Wouldntg hurt to verify ground wire connection on speed control. Check resistance to ground to verify wire is good.
 

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