2001 Mercruiser 5.7 TBI tach wire location?

[mnm99]

I'm looking for the wire to tie into so I can verify with another Tach that mine is working correctly. The reading I got off the - side of the coil seemed to be off by 400rpm with the last tach I tried. Is there a wire in the harness that I can tie into? I can't seem to find in in any wire diagrams.

 

[Bondo]

Ayuh,.... All tachs get their signal from the coil's (-) terminal,...... The only wire in the loom for it, is of course the Tach Wire,....

Well,... unless it's a Diesel, in which the alternator is used,.....