Mercedes Benz repair: power windows, mercedes benz 300d, benz 300d

Question
I have a 1978 Mercedes Benz 300D and only 1 window works how do i find the problem? Also my speedometer does not work all other gages are ok. Can you please help me? Thank you so much. Clara

Answer
take a multi meter to each console switch and verify you are getting vopltage at the console switch other wise if you are then you will have to tear each door apart individually and check for voltage at the regulator could be also your window went off tack . Your speedo cable probably got unplugged from the back of your cluster you will need to pull steering wheel and then pulll out cluster, you can also try to feel under neeth and try to replug in speedo cable (very difficuly cuz you can only feel where it is and need small hands