Points, but no condenser?? 75 450 SL

[Dusty4]

Is the condenser missing or somewhere other than in the distributor?? There is an unhooked green wire and a mounting screw for one... I note that my Performance Auto catalog lists point sets, but no condensor....I've never seen a points ignition system without one....Whats up? Thanks upfront, Dusty

[danwashuk]

Hi Dusty............I ran into the same thing with my 74 450 SL. Apparently it is supposed to be that way. I think there is a service letter from Mercedes about it. I tried to order one from a parts supplier and they told me about it, so just leave it out...........Dan

[meltedpanda]

really, I 'd like the reason behind this one since it prevent the points from arcing and prevents coil insulation breakdown by limiting the rate of voltage rise at the points , do these get replaced more often??

[230/8]

Covered in section 07.5-503...intended to reduce the coating that forms on points because of the discharge of the condenser.

230/8

[KCM]

Did a tune-up for a friend on a 1975 or 1976 450SL, ordered a condensor only to find out it did not have one. I concluded it was an early form of electronic ignition that used points instead of the magnetic pickup to fire the module. Not sure if I concluded correctly, but sounds possible.

[BrianB]

Bought one a year ago, now converting to points, nice to know there IS no condenser----I was puzzled!

[RadioTek]

On these Bosch systems, they switch the low current / low voltage side of the circuit, rather than the high current side. That is done in the electronics module behind the headlight. Since they're dealing with low current, the capacitor isn't needed, as in a situation where they're switching the high current or a coil with fewer windings.

The points just provide a low level variable length pulse to the module, which switches the input to the coil with power transistors. The waveform of the signal can be customized to match the electrical characteristics of the coil that way.

Hope I didn't glaze anyone over on that, with the technical terms.

Scott

[irshmerc]

Hi Scott, how you doing
I'm looking for the Google translator as i type
Good luck

Pete

[230/8]

Originally Posted by BrianB

Bought one a year ago, now converting to points, nice to know there IS no condenser----I was puzzled!

Uhhh, if you are "converting" over to the old-style point ignition, rather than using a Pertronix-style that eliminates points, or continuing to use the original transistor set-up, then you will need a condenser to avoid point burning. It is only omitted when you are using the original transistor set-up. You will also need to ensure the point plate inside the distributor is properly grounded and the right coil and ballast resistor are used to match the point set up.

[RadioTek]

The big "hitch" with a '75 is that the dizzy has a dual action vacuum actuator, for both advance and retard. The mechanics for that make it so that a Pertronix upgrade won't work (without extremely precise re-engineering). You have to go with the Crane - S&S system, which changes out the electronics package behind the Driver side headlight.

I had to do this, because age and time had given me 'shaft wobble' that was eating the rider on my points. I had to readjust them about every two months. Since I went with the S&S unit, I haven't had any trouble with the ignition. It just runs great.

Just my observations,
Scott