2007 Trailblazer Blower motor
Blower motor quit working. Found out motor was fine, control module was
bad. Ordered a new one that said it was for Auto AC control. When I
installed it the motor worked on all speeds and was fine for two days. Then
the front vents quit blowing air. This has been a problem since I bought the
car used. I could usually reset the vents using the steps I found on here.
But now the air comes out at different speeds and from different locations
like it is cycling through options or something. I can get the air to come out
of the front vents but not AC. When I turn on the AC it will blow out the front
vents and then blow out the defrost vents and then out of the floor vents.
Could it be the Blower motor control module is not the right one or isn't
working properly? Before I take everything apart to replace this unit I would
like to be sure this is causing the problem. Help.
Blower Motor control module is indeed for digital controls (Auto). If you have manual controls, it's called Blower Motor resistor. Both are different, but look the same, one will not work for the other. Make sure you have the correct one. Also, make sure you replace the pigtail that goes to it, these melt, which will ruin your new "module"
So my question is "if they sent me the wrong one (because I specifically ordered the Module) will that be the reason I am getting all of the NEW problems?" I can't see that it would be in the temp control module because I never had these problems before the motor quit working. When I put in the new Blower Motor Control Module (or resistor) the blower motor started working again.
Yep, could be your problem, they are not interchangeable. Any #'s on it or from the box? I might be able to look it up and see which one you have. You do have digital controls right?
Here's what it said on the website: "Fits These Vehicles With AUTO A/C CONTROLS - 2003 - 2006 Chevy Silverado 1500, 2500, Tahoe, Suburban | 2003-2006 Chevrolet Avalanche | 2003-2006 GMC Sierra 1500, 2500, Yukon, Yukon XL | 2003 - 2009 Chevy Trailblazer & GMC Envoy | 2004 - 2007 Buick Rainier | 2003-2006 Cadillac Escalade, EXT, ESV | And More, SEE BELOW for all vehicles. " Then it had---"High-quality OEM replacement parts,this HVAC AC Blower Motor Resistor kit is compatible with various OEM numbers 15-81773, 89018778, 89019351, 19260762, 15-80567, 52495874, 251946786, 52416100, 22754990, 15850268, 10325408, 10356906, 10397570, 15827470, 15827491, 52497491, 89018653, 89018849, 89018964, 93803635, 93803636, 973-508" Notice it says "with Auto AC controls" and I have auto AC controls. Two dials on each side of a window with digits for the temp settings and buttons along the bottom. I was on the Rock Auto website and they had the same info and listed replacements being 89018778 and 93803636 as being compatible. I even talked to someone at Rock Auto and these were the part numbers they gave me but I didn't want to wait two weeks for them to send it to me. If you can direct me to the right part and it's less than $75 I'll order it immediately. I've seen some listed for around $60 that do say "Blower Motor Control Module and Auto Temp Control" but now I'm so confused I don't know who to believe. Thanks for responding.
Pictured are manual controls uses blower motor resistor. The other version, digital (the one you have), is blower motor module. Not my TB, that's filthy! I can't stress enough, to change the pigtail that goes to it. If it's melted inside of the connector (hard to tell), will short out and act funny and or ruin your new part. Correct part for your Automatic climate control (digital) is 1581773 AC Delco #, which you list up top. You should be able to pick up an aftermarket one locally for double the Rockauto price. Use the part #'s on Rockauto for reference when shopping locally. Part #'s will likely be the same even if private labeled for them.
This is the "auto control", the one I think you have. Uses the Blower Motor Control Module AC Delco part # 1581773.
99% of the blower motor problems are the part we're talking about. Really should have been a recall, it's extremely common on every GMT360 model from 02-09. If when you've replaced it again with new pigtails, could be (rare), the whole unit shown above. Pull one out of a junkyard to check.
The AC Delco part # you listed, 1581773, keeps coming up as a "resistor" and not "control module". Sure you have the right part? Or are they using the same part number for both the resistor and the module? This is about as confusing as anything I have come across and I have four college degrees, unfortunately, none of them are in engineering.
