Wiring Issue with Tachs

[hbMoppie]

Okay guys, I have a riddle for you. On the 62 bert we just bought, have a mechanic doing a bunch of things to her to get her right. One of the issues was/is the starboard tachometer. When on starboard engine is running, the tach works fine. When port engine is fired up, starboard tach starts jumping around, and does not register rpms. The tachs were old, so we replaced both of them, but the problem continues.

I figure there is some weird wiring problem but our mechanic can't put his finger on it. Any thoughts?

Thanks

[In Memory of Vicroy]

Gas engines? If so, tachs picking up their signal from the alternators or from the points? Sounds to me like a faulty ground at the instrument panel.

UV

[hbMoppie]

no they are diesels. The volvos you love so much!

[Eddy G]

They still may be getting their signal from the alternators. Maybe to troubleshoot you could position the new tachs near the engines and run short temporary wires to see if it is a wiring problem.

Eddy G.

[Bruce]

Do you have any type of engine sync other than a Glendenning such as a morse micro commander or the such?

[In Memory of Vicroy]

Oh......well......could be a bad ground or 50,000 other things. I found regular prayer was about the only thing that helped with the dreaded Green Motors....

I did have the identical problem with my TAMD 30s and it was a bad ground in the instrument panel that was feeding one tach back through the other. Took me a long time to find....if I'd had CX back then I'd have just shot everything in sight, including soaking the back of the panels and taking apart and shooting every plug in the harness.

My condolances....

UV

[hbMoppie]

No we don't have an engine sync.

I will check the grounding of the tachs. Figure that may be the problem.

[Bruce]

Oh......well......could be a bad ground or 50,000 other things

UV,
You owe me a new keyboard. Funny shi* right there.

[Hueso]

same thing happening to my starboard tach......I have 454 crusader engines and morse sticks.....the only difference is that usually the tack works in neutral and when I accelerate the damn thing goes back to cero.....

Next weekend I will try UV's suggestion: spray the whole damn thing with CX......problem is I'm having trouble finding CX down here in Puerto Rico.

UV:

Can you ship it down here?

[bob lico]

and were having trouble getting that 151 proof up here .i wonder what is in that patron???maybee we should drink the corrosion x

[IRGuy]

Gee... It would think the two of you could arrange a trade!

[Craig Mac]

I replaced my tachs last year on a gas boat---used VDO gauges--also have problem with the starboard gauge---I spoke to tech and they have a bulletin regarding erratic readings---something about installing a diode ---

[In Memory of Vicroy]

Hueso - The Puerto Rico distributor is Galaxy Distributors (Harold Marquez) at 787.774.1330.....if he can't supply you let me know, I'll figure a way.

UV

[Hueso]

bob:

I'll find out if I can send you a bottle, but not the Bacardi boring stuff. Don Q is what we (I) drink. PM your address just in case.

UV:

Thanks a lot. Called today and Harold is a really nice guy. Found the CX. You drinking now a days?

[In Memory of Vicroy]

Counsellor, I am. Glad you found it.

UV

[Rocky]

I had tach readings like that on my gas engines and finally found the key on power to gauges were switched, so one power source was feeding opposite gauge. Look for switched wires in cluster to cover your bases.
It was feeding back to make the one engine read right , until you turned on the other. Just a thought to check!