[underdog]

I don't seem to have a signal from the MSD 7731 to the tac. It used to work fine. Wiring is a-ok for sure. I did lend my box out to a racer in need so his setting are in it. Is there a chance that the output is turn off or something?? I haven't yet gotten my head into this box as I used to have the 7al. Thanks for any help

 

[Sparky]

Dog,
I assume you are referring to a 7531, since I could not find a 7731. Depending how old the box is, you might have a choice of 2 tach signals. One comes out the end of the box and the other is in the 12 pin Detusch Connector, the Gray wire.

In the Data Editor under Cyl Cnt you can choose from Tach Trigger (Recommended) or Tach Timming, which generally isn’t used. Check to see if this is set to Tach Trigger, if it is, try both outputs on the box. If still no luck, you can either check the signal with a scope (Fluke 97 or equivalent). Or the easy way would be to check the Ignition with another known good Tach.

I hope this helps
Sparky

 

[underdog]

Thanks Sparky, I appreciate it.