Hi
The folding mirrors on that era E class is a very simple circuit.
I have no wiring diagram for it handy as the circuit is very simple.
Each folding mirror is wired directly to the console switch.
If you look at the console switch connector you will have 2 yellow and 2 Green cables, a brown which is the -ve, a black/blue cable which is an ignition switched +ve and gray/blue which is an illumination supply for the switch.
Diagnostic ignition on, from switch connector with multimeter set on DC Volts, check for Voltage across brown and black/blue cable, if there is Voltage there, move the positive of the meter to the green cable pin, and operate the switch, you should see a voltage across the green and brown cable in one of the switch positions, and in the other switch position you will see a Voltage across the brown and yellow.
All the switch does is swap the polarity of the supply on the mirror folding motors, to change there rotational direction.
If everything checks out so far then you have a break in the cabling from the switch to the mirror, this will most likely be in the mirror it self as they can get damaged due to constsntly folding.
My only thought are if folding mirrors were never a US option it means someone has retro fitted them and the colour of the cables may not be the same, if this is the case post back with a pic of the switch plug and I will identify the wires on your plug to enable you to carry out the tests above, if required.
Post back if I can help any further.
If you want anymore help don,t hesitate to post back
