Functional Testing - Pitch Trim Hat Switches on Stick Grips

Vertical power required pin-to pin circuit integrity testing, so most systems worked just fine when functionally tested, except the pitch trim hat switch on the pilot (L/H) stick grip. 
The R/H pitch trim hat switch was however working, so  the connectors were separated and compared. 

A quick comparison of the L/H and R/H pins both connector pins revealed pin 7 on the R/H side

but no pin in location 7 on the L/H side:

 

 

 

 

Per the schematic, pin 7 is the common for the hat switch, verdict : the L/H trim switch had no common to ground up (orange) and down (black) wires to. 

A quick jury-rig confirmed the fix:

A common was added to pin location 7 on the L/H pitch trim switch connector and proper function was restored.