Tach not working on 914-6, Not my car unfortunately... Options

[Nogoodwithusernames]

I'm trying to be of some assistance to the guy in town who is getting his -6 put back together and troubleshooting the myriad of little issues after a restoration. We already figured out that his speedo drive got swapped with a 911 unit at some point so he has the correct one on the way.

The issue at hand is tachometer isn't working. All gauges were rebuilt. I can't remember who he said did them but I recognized the name as a reputable place.

The tach has the purple and black wire hooked up to it, but there does not seem to be a purple and black wire back at the coil. Just the main wire to the distributor, and one wire on each terminal.

Any ideas of what to look for and check? Are we missing something obvious?

[ClayPerrine]

The 70 914-6 used a tach adapter, same as the 911. In 71, they changed it so the tach adapter was no longer needed.


Are you running the original CD box with the 123 distributor? If you are, and you have a 70 914-6, you will need a tach amplifier. The trigger voltage to the CD box is too low for the tach in a 70. Summit racing has tach adapters that will work. The MSD one I have used before. You just have to wire it into the relay board.

Or find a 71 and later 911/914-6 tach. Then all you need is a jumper wire on the relay board for the tach wiring.

Hope that helps!

Clay