I'm fairly new here, I have been slowly bringing a 1985 300sd back from the dead. I have lots of small issues but the main one since the weather as gotten cold is heat. I have been searching this issue for a week or so but need some more help.

I pulled the blower motor today since it was not spinning at all and found that the wires were corroded and plain ugly, I couldn't even get it to fire up on a 12v battery on the bench so I cleaned it all up, made some new connectors and now it would spin up on the bench so back into the car. now with the key in the on position, the fan blows in every mode of the climate control, changing vents, and all the good stuff but as soon as I start the car it all goes dead. I can feel heat behind the vents but the blower motor is not running in any mode, or at any speed.

What gives!

Thanks to all the great posts I have read, or I wouldn't be this far!

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1985 300sd
1984 Jeep CJ7 Chevy 350 Powered
1975 Honda CB750f
2006 Kawasaki ZZR600

Is it the electrical portion of my Ignition switch?
bump...for some help...

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1985 300sd
1984 Jeep CJ7 Chevy 350 Powered
1975 Honda CB750f
2006 Kawasaki ZZR600

I'll check my CD ROM FSM for wiring schematics if you're interested.

John

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Certified Registered Nurse Anesthetist (CRNA)
2002 F250 powerstroke with Plantdrive WVO conversion
1983 300SD 190K miles ,sold
2006 E320 CDI

I found a thread with exactly the same type of problem this morning. It pointed to the electronic part of the ignition switch. It seems that you can make it work if you jiggle the key after starting to get it to work sometimes. I will give it a try later, if it works I will replace the part, if not I will be back!
Thanks!

Matthew

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1985 300sd
1984 Jeep CJ7 Chevy 350 Powered
1975 Honda CB750f
2006 Kawasaki ZZR600

Yep,

on my 300cd I turn the fan on high and turn the key (wiggle) and when the fans goes I go.

Dave