Intermittent electric mirror position

[mrlightyear]

Drivers side electric mirror position adjustment intermittently works / doesn’t work.

They are non electric folding, just electrical mirror position adjustment and I think heated

Any ideas of fault finding, troubleshooting, solution etc.

Was potentially wanting to change the mirror & window switch unit anyway out as plastic coating looks a bit worn.

 

[Zulu4]

I'm part way through retrofitting power-fold mirrors so I've been stripping apart wing mirrors and door switches.
I found that one of my spare driver's mirror door switches was intermittent so I separated it and sprayed electrical contact cleaner on the contact pads. This also allowed me to spray paint the case satin black and now looks good.
Note that four little plastic rockers will fall out when you separate it. It took me about 10 minutes to figure out the jigsaw of putting them back in the correct position.

It is also easy to remove the mirror glass and spray something like ptfe spray onto the moving mirror mount. Do this while manually, or electrically, exercising it to make it easier for the motor to move.
Note that some mirrors just pull off, but others need a locking ring moved about 1cm left or right, visible behind the top of the mirror glass.