Help with Snap On MT Dwell Meters

[dogzbody1]

Hi all

I collected a pair of neat vintage Snap On Dwell Meters at a local garage sale, an MT 417 and MT 418, can't wait to use them on my little TR.

The MT 417 (Secondary Dwell) is in good physical condition but the inductive pickup (clamp for the plug wire) is missing, there is a gray wire that terminates a with metal connector but sadly no pickup. Does anybody have a source for these? (No response from Snap On for this or the manual). Any ideas for sourcing either the clamp or manual? Perhaps if I had the manual and schematic I might be able to bodge something together, any share similar experience would be appreciated.

The MT 418 (Primary Dwell) is also solid and complete, the wire with clamp that connects to the coil needs replacing but I figure its an easy solder job. I can't locate a manual for it (no response from Snap on) but I'm fairly confident that I won't find anything I can't handle inside. Still if you can't point me at a manual please do.

Thanks for any advice or leads that you can share!
Steve

 

[Bobioz1]

If your not doing a ground up restoration on it, take one from a used timing light.

 

[dogzbody1]

I was thinking about that, I'm looking for a manual which I would hope has a wiring diagram that shows me that is a workable solution.
Thanks!
Steve

 

[Milton Shaw]

To calibrate or check the dwell settings. The original GM computer systems fro 81 and up that had the electric carbs. When the system was first started it would generate an exact 30 degree dwell signal. I don't know of anything else that would give you a good reference signal that accurate. Any time the system was in open loop it was that 30 degree signal. After going into closed loop it would generate anywhere from 10 to about 60 to control the mixture. Problem now is finding a car in that range that is still factory stock too check that signal.

 

[dogzbody1]

Thank you, reference point will be helpful

 

[disston]

You can just compare the reading of the questionable dwell meter to a known good one. No reason I can see that both aren't hooked up at same time.

 

[dogzbody1]

good call!