# switch



## rusty baker (Feb 13, 2009)

How do you check a window switch to see if it is reversing polarity?


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## Windows on Wash (Aug 30, 2011)

You will need to figure out what the wire leads go to and via wiring diagram and see which ones are supposed to get voltage in the given switch positions.


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## msmith5554 (Apr 13, 2012)

Do not use a test light. Use a volt/ohm meter only. Most newer cars have a multiplex control unit that controls the power windows along with other systems as well. It's easy to short these out using a test light.


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## silverado454 (Aug 20, 2014)

Been a gmc tech for 4 years now, 10 years total, i've run across alot of newer gm vehicles, 2000 and up, the wires that run through the door pass through, by that mean the wires that come out of the door and go into the body, they can fatigue and break and it seems like the switch may be bad, u could use a test light at the power window motor to see if the corresponding switch is working


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## 95PGTTech (Jun 24, 2014)

msmith5554 said:


> Do not use a test light. Use a volt/ohm meter only. Most newer cars have a multiplex control unit that controls the power windows along with other systems as well. It's easy to short these out using a test light.


correct. backprobe the output for the switch. one direction should give you positive voltage, the other an identical negative value


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