Topic: tach wiring information

[ponchonutty]

I want to hook up a factory tach in my '70 bird.  The cluster is from a '71 and everything else works as it should.  I believe my '70 Espirit may have not came with the tach option when it was new.  I need to know what the pinouts are on the white plug that pertain to the tach functions.  I know there's the wire off of the ignition coil but don't know where that goes from there.  I have a '78 shop manual and it shows information for the regular gauge package (with out tach) but doesn't go into depth for the actual wiring for the tach itself.

[ta78w72]

None.  The tach doesn't connect via that IP cluster connector.  There's a special little harness that goes from the distributor through the firewall down near the bulkhead connector on the drivers side to the tach.  That's the signal wire.  There's another wire that plugs into the fuse box that powers the tach.  The tach gets ground from the cluster housing.