Date registered: Feb 2010
Vehicle: 1972 280SEL daily driver. 904 Dark Blue with cognac interior. euro 4.5 engine
Location: Williamsburg, VA
Mentioned: 3 Post(s)
Quoted: 39 Post(s)
Which power for Pertonix ignition
I know there are several threads about retrofitting Pertronix onto vintage Mercedes, but I have a specific question I can not find.
I have a '72 280SEL4.5 that seems to have suffered ignition module failure. Voltage to the primary of the coil does not change when the points open. I am ordering the Pertronix 1885 module with the flamethrower coil. I am obviously replacing the MB module since it is bad.
Question is, the new Pertronix does not need the ballast resistor in series so the 12v power source can go straight to the + of the coil, but what do I do with the other power source to the existing module. There is the 12V from the ignitin switch which feeds through the resistor, and the 12V from the starter relay that supplies 12V bypassing the resistor during cranking. For those who have done this conversion, I assume youran the 12v from the switch to the coil, but what did you do with the 12V from the starter relay? Pertronix says not to leave the ballast resistor in the source.
Any other issues with the 1885 Pertronix swap I should be aware of?