Perkins tach problem

Sven

Sven

Seglare
The tach for our Perkins stopped working during our cruise. The cable makes it look like a mechanical wire connection so I assume the wire is the problem. The hour meter also stopped working which makes me think it is a Hobbs meter rather than a straight hour meter ?

Any suggestions for how to try to fix the problem and where to start the diagnosis ?

Thanks,


-Sven
 
Tom Metzger

Tom Metzger

Sustaining Partner
I am not sure what you mean by a "mechanical wire". Is there another kind? :cool:

Assuming you mean an electrical wire, measure the voltage at the tach. It should be an AC voltage if coming from the alternator or a chopped DC voltage if coming from an engine pickup. Also check to see if you are getting 12 volts from the key switch on your instruments. That could explain why your hour meter also quit, if the two problems are related.

On a sailboat it would seem silly to me to put in a Hobbs meter running off the alternator; why bother?

If the tach is run off of a spinning wire cable like the old VDO Sumlog knotmeters then disconnect it at the tach to see if it is turning.
 
Sven

Sven

Seglare
Tom Metzger said:
I am not sure what you mean by a "mechanical wire". Is there another kind? :cool:
Click to expand...

Yes, an electrical one :)

Since I think it is mechanical and seems to also power the hour meter I don't see how the hour meter could be (practically) clocking actual time and assume it is instead proportional to the RPMs which I think is what a Hobbs meter does ?

I'll dig into the manual tonight but wanted to know if there were any standard "this is what breaks" or "this is what you need to adjust" answers.

Thanks,


-Sven
 
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