1970 250C Distributor to Coil wiring

[mgrocott]

The wire leaving the distributor, does it go directly to the neg. terminal on the coil? When the points are open I still read a dead short to ground on the neg. terminal of the coil. thanks

[ctaylor738]

Sounds like your condensor is bad.

Do you have the transistor box hiding under the battery?

[mgrocott]

The wire coming off the distributor goes to an electronic devise hidden under the battery tray. Can anyone tell me what this transistor devise is and can it be the problem I'm having. And that problem is I'm always reading a direct short to ground on the wire leaving the distributor and going to this electronic devise. I've removed the condenser and still have the ground and disconected the breaker points also.

[ctaylor738]

That is the MB transistorized ignition unit. It's purpose is to allow a good signal to the coil with a low voltage across the points which in turn prolonged point life. That's why you should have two ballast resistors - to drop the the voltage 'way down (can't remember the exact figure).

It is not unusual for the ignition unit to go south. The replacement is either a Crane or Pertronix setup. Both have web sites.

For more information, check out Randy Durrance's site:

http://www.durranceeng.com/ignition_diagram%201.html

[mpnye]

If the SWITCHING UNIT went TITS UP . . . REPLACE it with a Pertronix Igniter PLUS unit with their BLASTER COIL . . .

MUCH MUCH BETTER than the ORIGINAL ignition ! ! !

[gmask]

Originally posted by mpnye
If the SWITCHING UNIT went TITS UP . . . REPLACE it with a Pertronix Igniter PLUS unit with their BLASTER COIL . . .

Do you mean the Igniter II .. I can't find a plus listed on their website?

[mpnye]

Originally posted by gmask
Do you mean the Igniter II .. I can't find a plus listed on their website?

yes . . . that's it . . . the one with SMART Technology . . .

[gmask]

Originally posted by mpnye
yes . . . that's it . . . the one with SMART Technology . . .

I noticed in their PDF catalog that the Ignitor II is not for all models of mercedes allthough the 70 250C is specifically mentioned I could not find a specific listing for my car a 72 250 would it not be the same as the 250c?

Any reccomendations on who to buy these from? The few places I have looked at so far didn't list mercedes application although surely they could special order them. I have been thinking about having Randy Durrance rebuild mine but he's still recovering.

[mpnye]

Originally posted by gmask
I noticed in their PDF catalog that the Ignitor II is not for all models of mercedes allthough the 70 250C is specifically mentioned I could not find a specific listing for my car a 72 250 would it not be the same as the 250c?

Any reccomendations on who to buy these from? The few places I have looked at so far didn't list mercedes application although surely they could special order them. I have been thinking about having Randy Durrance rebuild mine but he's still recovering.

If you want the BEST performance ? ? ?

Get an late version ALUMINUM BODY Distributor and install a Pertronix unit in it . . .

That's what I do . . .

[gmask]

Originally posted by mpnye
If you want the BEST performance ? ? ?

Get an late version ALUMINUM BODY Distributor and install a Pertronix unit in it . . .

That's what I do . . .

Where would I get a late version aluminum body distributor?

[mpnye]

They're about the ONLY ones you can get anymore, unless you're restoring a car and are willing to buy a NOS cast iron one . . .

[gmask]

Originally posted by mpnye
They're about the ONLY ones you can get anymore, unless you're restoring a car and are willing to buy a NOS cast iron one . . .

So then the new distributors for sale through every online parts place including Fastlane are the type you speak of?

[mpnye]

yes . . . the cast iron units haven't been available for over 25 years . . . whoever carries Bosch can help you . . .