Odd blower motor problem

silver007

Original poster
Member
Sep 2, 2018
16
GA
07 TB LS with manual climate control.

No blower on any setting, completely went out all of a sudden.

Tested motor, turns with 12v.

Resistor showed .1 volts one tenth of a volt at most speeds 1-5 on blower plug so I get another resistor. New resistor shows speeds 1-4 are .11 volts, that's one tenth of a volt. Speed 5 shows 0 volts. Do I have a bad new resistor? Big connector looks ok. Edit- connector looks to have gotten hot at terminal C, others look fine, actual C terminal looks fine. ? Do I need to do more tests?

Checked fuses 35, 36, 39 and 44.
 
Last edited:

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
I had something similar happen to me a few months ago, where my blower was inconsistently working. After back tracing and chasing voltage readings, turned out to be my ignition switch had gone bad. One of the "Run" connections inside it, is specific to the HVAC circuit. replaced that, and my blower functionality came back. Here's the wiring diagram.

1642985818432.png
 

silver007

Original poster
Member
Sep 2, 2018
16
GA
I just tried a spare ign switch and now I have speed 5 only. Abs/Trac/brake lights are coming off and on when I switch the climate on and off speed 5. Maybe both my ign switches are bad. Can you verify what the gear on the switch is supposed to look like when key is off and I pull the module out? I've got all teeth showing. Maybe they're both a tooth off?
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
I don't have anything that shows where the teeth are aligned, but if you suspect you might be off, go ahead and adjust your switch by a tooth, and then see how it behaves. Depending on the change, you could try going a tooth in the other direction from the starting point.

The HVAC controller shouldn't have any affect on the traction control system, so I'm not sure why those indicator lights are responding to those inputs. Wild guess would be maybe a ground issue? The one on the passenger side floor of the radio stack is one we frequently check when troubleshooting anything inside the dash console.

If you don't already have the service manuals and wiring diagrams, you can get them from this thread.

 
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Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
To align the switch gear teeth, I'd try this (never done it but just thought of it). With the switch pulled out, turn the gears until you get to the RUN position where you get spring resistance from the START position. Then turn the key to the RUN position before the START position and then insert the switch.

The OFF position may be anywhere but the RUN position is pretty constant.

For funky electrical issues like that, check the main ground block bolted on the right side of the tunnel. It's under the carpet.
 
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Chickenhawk

Member
Dec 6, 2011
779
If the blower motor resistor has been changed, the next suspect is the connector. If there is the slightest bit of darkening on the connector, solder in a new connector. This is a very common failure, and you can get the connector at most auto parts stores. I cut off the old connector, stripped and soldered the wires and use shrink wrap insulation. Solved all my blower motor problems.
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON

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