Mercedes: 1981 Mercedes 300TD, No power!, mb tech, mercedesshop

Question
For a few months we have had a problem with the ignition not turning at all. So just a few days ago we installed a new ignition switch and now the car starts and runs great. But nothing works. Not a single electrical appliance. No turn signals, no power windows, no radio, no head lights, nothing! But when the car is off the overhead lights work fine and when I engage the starter, everything works fine for just a split second while the car is cranking over until it starts running and then nothing works. Could this have been causes by a rewireing error? And if so how can we fix it.

Answer
Answer:
You have a W123 Station Wagon:  
Chassis 123.190
Engine 617.912
Model 300TD Wagon
Years 1979-81
Weight 3740
Wheel base 110.2

I suggest joining the following forum, as several senior members (can help you hands on) are local to you.

Diesel Discussion
http://www.mercedesshop.com/shopforum/forumdisplay.php?f=15

Texas
http://www.mercedesshop.com/shopforum/forumdisplay.php?f=74

You will need this sooner or later.
MB Tech Manuals from MBUSA cost $19.99 plus S&H
http://www.mercedesshop.com/shopforum/showthread.php?t=142445