The tachs for my Perkins
4-236 engines function by a pulse coming from the alternator
to the tach itself. This is not too satisfactory, because when the batteries are fully charged (as they usually are when I first start up the engines) the tachs do not work, since the alternator
is not putting out current
to the batteries. This would not be too bad in the slip, but continues for quite a while after getting underway.
So I am thinking about replacing them. Aetna engineering seems to have some nice ones which their website says will work with my engines and connect to an SAE type mechanical drive fitting.
Does anyone have any experience with this that they would be willing to share?