I have recently encountered some difficulty with the operation of the power passenger mirror on my 88 560SEC. The switch on the console does not seem to adjust the mirror.

Would any one be able to shed some light on this matter? Thank you in advance.

First check your fuses. If not the problem then you can disconnect the mirror from the power connector. That connection is in the mirror housing. Gently pop out the shiny plastic triangular piece with a flat head screwdriver to expose the connector. Then put a meter on the pins of the connector and test the 4 positions on the mirror adjustment control knob. Identifying the pins and their corresponding mirror position is hit or miss at first but you will get the hang of it. You may need a helper to move the control knob while you hold the two multimeter leads in place. Have a piece of paper handy to right down what your find out or you will drive yourself crazy. If your not getting power to all 4 positions, your mirror adjustment knob most likely needs to be replaced or the power connector to your mirror adjustment knob is detached (located under the console). If your getting power to all the positions and the mirror still does not move, your mirror motor may be locked up but not likely cause there are two motors in the mirror housing and both of them going bad simultaneously is not likely.