GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
Do the temp doors work?
temp doors work. mode door to blow from mid level vent works. only switching from defrost to feet inop.
Did you get the upper lever that hooks into the slider engaged?
everything is engaged. the actuator does not move even when not connected to the door.
Ok then if the door moved freely with out the actuator then I would suspect the heater control itself.
could it be the control if the only thing that doesn't work is the defrost side?
WEll, lets discuss this, the actuator is not the issue or it would have been fixed when you replace it.
The wiring is not bad or it would not change at all.
The door moved fully when you did it by hand, correct?
is that the only thing it could be. priced the control unit and it is $260. and yes the door moved freely.
moving the door manually without the actuator connected would correctly change where the air comes out.
Unless you assembled it incorrectly, then that is all that is left as far as I cans ee
what do you mean by incorrect assembly
that you put it together wrong when you replaced it.
No offence but it happens to all of us, myself included. IT is the reason I learned so mych.
it would only go together one way if i wanted to get the gears aligned correctly and have the cam line up with the actuator and the mounting holes. does that sound correct? no offense taken. i used to do mechanic work 20 years ago but not for a long time so i just wanted some advice.
IT can but the sliding lever can throw you for a loop when assembling, but if you got it all together and it turned by hand, meaning you pulled the large disc off the actuator and moved it by hand then that should confirm it.
i did also take a 12v test light looking for power to the actuator. one wire has power. two of the other wires made the actuator move in different directions when i touched the test light to them.
THere is a feedback circuit, power, ground and signal .
i guess i will need to find the control unit and replace it. ouch!
do you have any other advice on this subject?
Double check everything one more time to see if you overlooked something and check the wiring back to the module from the actuator.
could these other two issues be related? the service tire monitor and service air bag notices intermittently appear on the cluster display.
Nope, those are tire sensor(s) and the wiring for the air bag or sensor.
i will check one last time, but i did not see anything unusual about the wiring from the actuator to the module.
Always good to double check. I always did when diagnosis called for a module.
i did find one online for $170. at least it is cheaper than the dealer.
thanks for your help
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