HVAC Blower quit working.

[08H3]

Need some quick help. Today the heater blower stopped working. The first time it happened there was about a two second delay between the time I started the truck and the fan kicked on. Knew it wasn't right but thought nothing of it. Everything seemed fine. Couple hours later went back and there was no fan at all until about 10 minutes into the trip. At that point it came on, worked fine for 10 minutes or so. To "test" it I turned it off and it has not come back on since. Checked all the fuses that I thought pertained to the fan. All checked out fine. Pulled the blower resistor and although I admittedly have no idea what to check, it visually looks fine. Netiher the resistor or plug show any heat damage.

Any ideas? I was to leave on a vacation early Thursday, but I can't drive in this weather with no heat and I'm not sure the dealer can get me in before then.

Thanks in advance.

[Flash]

1. That sucks.
2. One of the best things I like about my Hummer is the heater. By far - the best ever!!! Unbelievable how fast it heats up the cab. 6 minutes into a run and I have to turn down the heat.
3. My Reatta ( at 18 years old) needed an occasional squirt of either WD40 or Electrical contact cleaner to keep dash lights working (via contacts on the push buttton switches).
4. If you pulled contacts, try a squirt of WD40 or (CRC) electrical contact cleaner. I am just guessing - but based on my experience with the Reatta, I would try it.

[Seth]

Any ideas? I was to leave on a vacation early Thursday, but I can't drive in this weather with no heat and I'm not sure the dealer can get me in before then.

I have no idea about how to solve your problem, but that would be pretty sad if your dealer couldn't fix you up by Tuesday. I usually get same day service without an appointment. Only thing that usually holds up the completion date is if they have to order a part.

[08H3]

I have no idea about how to solve your problem, but that would be pretty sad if your dealer couldn't fix you up by Tuesday. I usually get same day service without an appointment. Only thing that usually holds up the completion date is if they have to order a part.

Only basing that on my own doom and gloom attitude and the possibility of having to order parts. Don't hold anything against the dealer...yet.

[f5fstop]

Is it not working on ALL speeds? (In the HI position, the blower motor ground circuit bypasses the blower motor resistor pack. So, if it works on HI, most likely it is the resistor pack.)

Did you check all of the fuses?
HVAC BLWR 30A Fuse 82
HVAC CNTRL HD 10A Fuse 59
RDO Fuse 10A Fuse 13 (If this one is blown the radio will not work either.)

Another suggestion, switch out the HVAC Relay (number 87) with another identical relay in the fuse panel (I believe the A/C Clutch Relay (number 76) is the same type of relay. The HVAC relay supplies the main power to the blower motor through fuse 82. To switch out a relay, just pull it straight out. MAKE SURE when swapping out relays to compare the relay part number, which is in plain sight on the top of the relay. IN ADDITION, MAKE sure you note how they go into the slots. Usually, not possible to insert incorrectly, but we all know Murphy’s Law.

You can always, disconnect the blower motor’s two pin connectors and run some jumper wires; 1 from the battery (BROWN WIRE, Terminal 2), one from ground control circuit (ORANGE, Terminal 1). This will simulate the BLOWER motor on the HI speed circuit (no resistors in the control circuit). If the blower motor now works, it is a wiring problem in either the blower motor power or ground control circuit, or a defective blower motor control module.

[08H3]

Is it not working on ALL speeds? (In the HI position, the blower motor ground circuit bypasses the blower motor resistor pack. So, if it works on HI, most likely it is the resistor pack.)

Did you check all of the fuses?
HVAC BLWR 30A Fuse 82
HVAC CNTRL HD 10A Fuse 59
RDO Fuse 10A Fuse 13 (If this one is blown the radio will not work either.)

Another suggestion, switch out the HVAC Relay (number 87) with another identical relay in the fuse panel (I believe the A/C Clutch Relay (number 76) is the same type of relay. The HVAC relay supplies the main power to the blower motor through fuse 82. To switch out a relay, just pull it straight out. MAKE SURE when swapping out relays to compare the relay part number, which is in plain sight on the top of the relay. IN ADDITION, MAKE sure you note how they go into the slots. Usually, not possible to insert incorrectly, but we all know Murphy’s Law.

You can always, disconnect the blower motor’s two pin connectors and run some jumper wires; 1 from the battery (BROWN WIRE, Terminal 2), one from ground control circuit (ORANGE, Terminal 1). This will simulate the BLOWER motor on the HI speed circuit (no resistors in the control circuit). If the blower motor now works, it is a wiring problem in either the blower motor power or ground control circuit, or a defective blower motor control module.

Thanks for the help. I did swap relays, but that did not solve the problem. I did check both 82 and 59 but not 13. Radio does work though, so I guess that can be ruled out. If it warms up, I may try jumping directly to the motor, but as cold as it is I may likely end up calling the dealer first thing tomorrow and hoping for the best.

[Ryan Graham]

It's probably the blower resistor. I've done a couple on Colorado's and on the other chev trucks. Sometimes the connector to the resistor is melted so you will have to replace the resistor and pigtail (your dealer will have them in stock). I agree with F5 in that the "HIGH" setting should bypass the resistor, but I have done more than one that the blower was entirely inop due to the resistor. Let us know

[f5fstop]

Then to prove out the resistor is just supply a ground from the blower motor to a good ground point. If the blower now works it is the resistor. Easy to do...but if under warranty, let the dealer screw with it.

[08H3]

...but if under warranty, let the dealer screw with it.

And that's what I decided. I'll post the findings.

[Lyn-X]

Mine did the same thing awhile back: viewtopic.php?f=25&t=11011

[08H3]

Just for anyone curious, it was the resistor. Looked fine to me, but apparently it was bad. Back to being nice and toasty now, but the 70 mile drive to the dealer with no heat and 15 outside temp was not pleasant. Have to give credit to good service when I come across it. Kelley Auto Group in Ft. Wayne got me in without an appointment and back on the road. Even washed the truck for me. It's cleaner than it has been in months.

[stjames151]

At least its fixable. Most of the H1's I've been in must've used the same 24v blower motor as the HMMWV and it sucks under all circumstances.

[CBphoto]

Glad they got it, that was actually a simple one...mine went out before, just lower the glovebox & unscrew the resistor from the airpassage, it's usually VERY obvious when it goes bad...only takes 5 minutes to fix.