Any thoughts are appreciated.
HouseCallAuto 9/5/2012First of all I am interpreting your details as that the blower motor is "NOT TURNING ON". If you are saying that there is air blowing, but the air is simply not blowing out of the front vents you will update the post and clarify. Run direct power to the two terminals of the blower motor to test it. 12 volts and a ground. If it does not run then replkace the blower motor and the blower resistor together.
Then it is as I said. Under the dash from the passenger side, remove the plastic sound insulator cover to expose the HVAC housing and blower motor (the round looking part of the case pointing down). Unplug the connector from the blower motor and you can check and see if there is battery voltage on one wire (the purple wire) and the black wire always remains a ground. Check for battery voltage with the key on and the blower turned on. If you have 12 volts on the purple wire and a ground on the black wire and the blower does not run, then the blower motor is junk. Check that and update me and I will continue with the next step later tonight. If there is no voltage on the purple wire make sure the fuses are good. the fuses you need to check are labeled HTR / AC (30 amp) located in the instrument panel use box. Also check the 40 amp maxi fuse labeled BLOWER in the underhood fuse panel.
You can buy a simple 12 volt automotive test light for like $10. Clip the lead on a good ground (like a door hinge bolt or similar) and use the pointed end to touch your voltage source (the purple wire pin in the blower motor connector). If the test light does not illuminate at first, make sure that your ground connection is good by jiggling it while touching the purple wire just to be 100% sure that you really have -0- volts reading if that is the case.
15862656 is the part # for the melted connector and wires (comes as a splice pack)
89019089 is the part # for the resistor if the truck has a console
89019088 is the part # for the resistor for without console
The bulletin is a TSB which is not a recall. I have repaired this at least 3 times on various GM trucks. Don't let the burnup scare you. Get the connector and the resistor but I strongly recc you also replace the blower motor as well because the amperage draw from the old motor may be a contributing factor in the meltdown and again I would use ACDELCO only as there have been documented instances where the aftermarket brands on this application draw too many amps even when new and cause the same meltdown to repeat.
I recc you use genuine ACDELCO parts which these part #'s are for.
HouseCallAuto 10/5/2012Chris, the #1 cause of no 4WD on most GM 4WD systems is the encoder motor that is attached to the outside of the transfer case. I want you to ask around and find someone who can read the transfer case codes for you for a small fee (like $25) or less or else start reading the details for all the various code readers in the $100 to $200 range for one that supports GM transfer case codes, anyway, bottom line is get me a fault code so I can continue and get your car out of that 1200 to 1800 place because your cause could simply be the encoder motor which you can replace yourself easily for under $200.