Erratic Tach.

[Jim lanza]

Encore, our 1988 Albin 40 sundeck has provided us (so far) with 21 months of interesting experiences. As a sailor of over 30 years, my experience with complicated systems and twin 'monstrous' Lehman diesels was limited. Over the past year and 9 months, I've learned a great deal about Encore, fixed a lot of minor irritations that I'm able to blame on the previous owner, who treated Encore as a floating condo and never moved her for at least three years. Encore has, in spite of minor issues, been a pleasure to own. But now I'm vexed by 'erratic tachs'. I have two Balmar H.O. alternators, that are pushing out 13-15v when running. I know that the tachs are not cable driven, so I am assuming that there's a problem with the wiring. Are any of you familiar with the Balmar wiring and how it connects to the tachs? I know that after 30 years, the tachs might be at the end of their natural life, but before I sink a boatload of cash into new instrumentation, I'd like to know if there's a 'fix'.

Hoping for some sage advice.
Jim Lanza
M/V Encore
Punta Gorda, FL

[jleonard]

I have a Balmar also. There is a wire that attaches to the alternator with a spade connector. Both times when my tachs went flukey that's where the problem was. Once it was loose, once it was corroded.
That's where I would look first. It could also be a bad ground.

[jleonard]

I found a picture of the corroded connector. I am at a loss on how this could have gotten so corroded. Nothing around it was affected and this is high and dry in the engine room.

IMG_0966.JPG

[RobS]

I found a picture of the corroded connector. I am at a loss on how this could have gotten so corroded. Nothing around it was affected and this is high and dry in the engine room.

Maybe you spilled your beer on it

[kchace]

One other possibility - if both tachs are feeding the same battery bank and that bank becomes or is completely charged, one or sometimes alternately both alternators will "shut off" which kills the tach signal as well. Now that I have solar charging sometimes the batteries are totally topped off and mine does this. If I change banks via the batt switch I can change which tach does it.

Ken