Tach Sending Unit - 6V92TA

[Glenn Allen]

I am trying to issolate why my tach is not working. I am starting
with the sending unit. After a little help, I have finally found the
sending unit.

The unit looks like a gearbox with an A-Frame clamp holding it to the
engine block. On top of the gearbox is a Hex column about 3-4" long
with an flat-1" dia circular electrical connector on top with two
wires exiting.

Has anyone performed any trouble shooting on this type of sending
unit? Do I remove the A-Frame clamp to check the gear box? Is there
an easy method to check the pulse output short of using a scope?

Thanks,

Glenn Allen
1986 PT-40
Marietta, GA