Setting Dwell on transistorized ignition

[ptspringer]

I'm trying to tune my 1972 350SL (4.5) which has transistorized ignition. As I understand it, the mechanical points inside the distributor switch a small voltage to the transistor "switchgear", which drives a much larger current to into the primary circuit of the coil. I'm afraid if I hook up my dwell meter incorrectly, I could put too much voltage into the input of the transistor unit (why is it called a switchgear?) and burn it out. I have an old timey dwell meter that has a switch on it for transistorized ignition. How do I hook it up? (across the coil leads, from one of the leads to ground, which lead)

Thank you,

Paul

[Arthur Dalton]

Pos + [ Red lead] hooks to terminal #7 at switchgear. Neg [ blk] to ground..

..or , red to output of .4 ohm ballast and blk to input of .6 ohm ballast.

It is easier to pierce the green wire from dist than to go back to terminal #7
if using first method.

Not familiar with your tester, but a normal dwell meter feeds no voltage into a circuit, just takes a reading.

[ptspringer]

Hi Arthur,
How do i tell input from output on the ballast resistors? Which side is the coil on?

[Arthur Dalton]

Go here.

http://www.sl113.org/forums/uploaded/ja17/20065180233_dwell1.jpg

Some have the terminal block on the wire going from dist to switchgear as shown, but some do not, which is why I mentioned pin #7.
If you have it, it is easier than going between ballast.

Many just put a terminal on the green wire near the dist for easier future dwell setting access..

I have seen many references to the term Switchgear, but mostly in UK publications....

Also, for future post, you are better off with a single post..double posting usually wind up in confusion for both you and the posters/readers...

[ptspringer]

You've been a great help.

Paul