1973 Mercedes Benz 450SL spark problem
 

Hi, I'm a new member to this forum and I'm at wits end. I have a 1973 450SL. I went to change the cap and roter. When I put it back together
it will not start. A friend and I traced a spark problem back to the coil.
When the ignition in in the first position, I get a spark from the coil, but when cranking, no spark and when I turn the ignition off I get a spark. I get this when the coil wire is removed from the distributor, so that eliminates the distributor as a problem, ....I think. Can anyone help me?
Also, does anyone know where the "brain" is located on this model. THanks in advance. I am sooooo lost.

Dagget

It sounds like your points are closed and not opening. Verify the points are set correctly (and not broken) before proceeding further.

If you file the points, use a dollar bill to clean the points, leaves no residue.

One other thing to check after the points:

Check the two voltage resistors for the coil, they look like the old Chrysler units. They drop the voltage so that full battery voltage doesn't go to the coil when the car is running and starting. Just hook a test light to the positve side of the coil on see if you are gettin voltage when the key is turned to the start position and then when the key is in the on position. I think one has a blue band an one has a red band.

1973 Mercedes Benz 450SL
 

Thanks all for their input. I'm assuming the Chrysler type ballast was bad, because I now have spark when cranking at the coil. Thanks again!! Love this forum!

Dagget

Glad to hear it all is well. :)