Yanmar Tachometer wiring question

bluey

Seaman
Joined
Oct 31, 2010
Messages
70
Hi,

Does anyone have knowledge about the wiring of Yanmar Magnetic Pickup Tachometers?

I have a 20' boat with a Yanmar 2qm15 Marine Diesel engine. It came without a Tacho when I purchased it, but I've since found a second hand Yanmar Tacho and would like to install it. However, I am really confused about the wiring involved.

Early model Yanmar Tachos ran off a magnetic pickup unit which pulsed off the teeth on the flywheel. I do have a magnetic pickup on my engine which has two terminals for wiring.

The Tacho I bought is a later model than originally supplied for 2qm15. It has an hour meter which the originals did not have, but I think it will work with my engine because my flywheel has 116 teeth and the Tacho is numbered "P116" so I assume it is the correct type for my flywheel. The Tacho has three wires protruding from the housing coloured = 1 Orange, 1 Black, and 1 Red/Blue.

DSCF2399.jpg

DSCF2400.jpg

My problem is that I have found three wiring diagrams and they all conflict with each other as to which coloured wires go to the magnetic sending unit and ignition. One diagram is from the early 2qm15 user manual, another is for 2qm20/3qm30 engines which would have used the later model Tacho. And the third diagram is for the "B-Type Instrument Panel" which I think may have been used with this Tacho.

1. 2qm15 Wiring Diagram.jpg
2. 2qm20-3qm30 Wiring Diagram.jpg
3. B Type Instrument Panel wiring.jpg

Can anyone tell me what the correct path is for each of the 3 coloured wires on my Tacho, please?


Thanks,
bluey
 
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