Blower control module installation issues [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: Blower control module installation issues


RzaBlade
07-16-2011, 07:32 PM
Thanks for the urgent assistance, as I have been driving around in the summer AZ heat with no air.

I recently ordered the part (89018778) that was recommended for my truck, but it has a 5 pin plug into the module, with 3 loose wires and a two prong plug type harness. The module that is under the dash is part 52495874 with a 3 prong plug.

Searching for the original part number eventually leads to the part number I purchased. What am I missing here?

Thanks again for the help.

RzaBlade
07-16-2011, 07:38 PM
<looks at the ground, ashamed>

Apparently I just need some electrical tape. Doh.

RzaBlade
07-16-2011, 09:00 PM
OK, got the blower control module installed and no fan activity, no matter the setting. I checked the fuses and everything looks good.

Should I proceed with replacing the actual blower?

pejeeper
07-17-2011, 10:33 PM
Not quite following here...
I think you replaced the blower motor resistor pack (look in the sticky section)and your blower fan still won't spin?

The blower itself is only a few bolts more so that's not a worry...it could be burned up.

The 5 pin harness coming from the truck and connecting to the resistor pack is my focus. Did any of the pins or wires look burned/melted? If so, then you need to clip the old harness out and splice in a new harness. TIP: cut & splice ONE wire at a time.

RzaBlade
07-17-2011, 10:38 PM
Yes, I replaced the resistor pack. I got everything spliced in and the blower wouldn't spin. I have since pulled the blower out and didn't see any evidence of burned out wiring.

pejeeper
07-17-2011, 10:45 PM
It is possible that your blower switch crapped out. I haven't had that issue so I can't weigh in on that..search this forum and the OE issues forum for that help.

Just a thought....have you checked the underhood fuses and the fuses under the rear seat?

bromanjr
07-17-2011, 11:31 PM
Thanks for the urgent assistance, as I have been driving around in the summer AZ heat with no air.

I recently ordered the part (89018778) that was recommended for my truck, but it has a 5 pin plug into the module, with 3 loose wires and a two prong plug type harness. The module that is under the dash is part 52495874 with a 3 prong plug.

Searching for the original part number eventually leads to the part number I purchased. What am I missing here?

Thanks again for the help.

There are 2 different modules used on these trucks, they are not interchangeable.
The manual system control has 2 temperature sliders in the center, these use a module with a 7-pin connector.
The auto system has a digital display in the center, this one uses a module with a 3-pin connector.
Both have 2 wires coming out with a connector for the blower motor.
I am puzzled by your description of a 5-pin plug? Maybe a picture of the old and new part?

The part number you mentioned is for the Auto System (RPO CJ2) do you have the auto or manual?

RzaBlade
07-18-2011, 12:01 AM
I have the auto system with the digital reading in the center. The original part had a 3 pronged connector (red, black, signal) and the purple/orange wire hardwired that went to the blower

When I searched for the part it led me to an upgraded model where the 5 connectors are consolidated on one plug, which involves snipping and splicing in the new harness (which is what I did).

The original symptom was erratic fan behavior, not shutting off after ignition was switched off, etc. Eventually all fan activity stopped no matter what setting was selected. Replacing the module didn't restore the fan, making me think that it has failed as well.

pejeeper
07-18-2011, 11:40 AM
The chassis harness is a 7 pin connector...sorry, i had a brain fart...and I have the manual controls for reference

bromanjr
07-18-2011, 01:42 PM
I have the auto system with the digital reading in the center. The original part had a 3 pronged connector (red, black, signal) and the purple/orange wire hardwired that went to the blower

When I searched for the part it led me to an upgraded model where the 5 connectors are consolidated on one plug, which involves snipping and splicing in the new harness (which is what I did).

The original symptom was erratic fan behavior, not shutting off after ignition was switched off, etc. Eventually all fan activity stopped no matter what setting was selected. Replacing the module didn't restore the fan, making me think that it has failed as well.

Every time I search for that part # I get the 3-pin connector style. Were there actual instructions to convert to this "new style" module?, was that part # actually on the part?

Is it possible you spliced in the new one incorrectly?

RzaBlade
07-22-2011, 08:39 PM
We'll see - my new blower arrived today and I will be putting it in this weekend. I suppose I will know more once both new parts are in.