tach problem

[no1shep]

i have a '05 21' trophy w/4.3 mpi merc.have had numerous problems with it.only used about 20 hrs.my problem now (other than overheating) is my tach.it stopped working within the first year.where does the tach feed from? i've tried following the wiring diagram in the merc.repair manual i bought. any advice?

 

[Bondo]

Re: tach problem

The Tach is fed from the (+) side of the Coil,........

My 1st Guess is,........
The Tach itself is probably Shot..............

 

[Don S]

Re: tach problem

The signal for the tach comes from the ECM, not the coil. Check for continuity on the gray/white wire between the ECM and the round 10pin connector.

 

[no1shep]

Re: tach problem

don s,bondo,thanks for the advice . i'll let you know what i find as soon as i get another day off to check.