pgamboa

Hello Phil hope you can help.  First off this is my first time posting on a forum, So pardon the blunders and I did message you also.  LOL

I have a pre 15 Chevy Silverado 3500 HD mfg 8/2014.  I had the original black mirrors with turn signal in them, then purchased newer ones with the marker lights(also purchased the harnesses).  Now I want to upgrade to the power folding mirrors. 

I came across a great deal for a used pair from a 2017 SLT Sierra (I do have vin if you need it) and have installed them however, the passenger side mirror will not fold in.  Here is some additional information:  I have the right harnesses, #23387133, #84290982, and #84290965 and purchased the GM mirror switch. My truck has memory seats, heated mirrors,  blinker in mirror and puddle light.   So far, memory mirrors, blinkers, puddle light and heat all work.  Folding option works on Drivers side mirror but not on the passenger side.   

Here are my questions, since I purchased these used 1.  Is there a way to test the motor of the passenger side mirror?   and 2.  Do I have to do something special in order for the passenger side mirror to work?  You help would be greatly appreciated.  John

Anyone else have any ideas, please feel free to chime in.