Synchronizer gauge stopped working

[AllanS]

Is it possible, likely that the flex cables are worn, and that causes erratic RPM signals to tachs?

 

[Skybolt]

Is it possible, likely that the flex cables are worn, and that causes erratic RPM signals to tachs?

No, it's not your "flex Cables". Worn would mean break, dirty would cause bouncing on a mechanical tach that would smooth out after a little while. Your issue is old defective tachs. Can they be sent out and rebuilt? Maybe. Your issue is the tach's themselves. Very common on older boats.

The Aetna's are your best fix and will last a very long time.

 

[AllanS]

Ok, you convinced me…better start saving my $ for the Aetnas!

 

[Skybolt]

Ok, you convinced me…better start saving my $ for the Aetnas!

Wise decision and one you won't regret.

 

[AllanS]

Hi guys, it's been awhile, but I thought it would be helpful to follow up. Yes, indeed, you guys nailed it, the tach signal originates from flex cables attached to the front of each engine, which connect to tach sending units located on each side of the Glendining synchronizer. Wires from those sending units can be traced going up to the helm to the Teleflex tachometers. Pictures below.

 

[AllanS]

Will the Aetna Engineering tach work with my sending units?

 

[dtfeld]

Will the Aetna Engineering tach work with my sending units?

If your electric senders are operational, yes. The Aetna's are almost plug and play. They are slightly smaller so you need a trim ring to physically mount them in the hole.

Setup requires setting the # of pulses per revolution (PPR) on a set of DIP switches on the back of the Unit. Since you have mechanical senders attached to the Glendinning unit, you need to figure out the PPR for your current senders. Likely that is 8, but could be something different. Call Aetna, they probably know off the top of their head.