Tach & Gauges

[steersdad]

I have just bought a used 2007 F 20 PLR. Like a baby version of my F115...

I want to install a tach, and the Rigging Guide I have (2012) says the only tach that work with the 20 HP 4 stroke are the "tach only" gauges. Which is OK with me, except I can't find one.

The part number they specify is 6Y7 83540 20 (or 30) black or white dial face.

Does anyone know if the "pro series" 6Y7-83540-80-00 PRO SERIES II TACH are compatible with my 20 horse 4 stroke?

Many thanks.

[boscoe99]

Appears that the 6Y7-83540-20/-30 are not sold here in the USA.

The 6Y7-83540-80-00 or -90-00 will work with your motor. Only thing is that the warning lights will not normally illuminate.

You can make them work if you care to fiddle with the motor so that the ground signal that is applied to the light assembly on the motor is connected to your tachometer. That will take a bit of local engineering and craftsmanship on your part.

[steersdad]

Appears that the 6Y7-83540-20/-30 are not sold here in the USA.

The 6Y7-83540-80-00 or -90-00 will work with your motor. Only thing is that the warning lights will not normally illuminate.

You can make them work if you care to fiddle with the motor so that the ground signal that is applied to the light assembly on the motor is connected to your tachometer. That will take a bit of local engineering and craftsmanship on your part.

Thanks. Do you use the on-board light signal to energize a relay to apply power to the indicator in the tach? Do you, by chance have a schematic or can you reference the proper schematic to look at?

Thanks again.

[boscoe99]

Thanks. Do you use the on-board light signal to energize a relay to apply power to the indicator in the tach? Do you, by chance have a schematic or can you reference the proper schematic to look at?

Thanks again.

12 volt power is applied to the lights in the tachometer whenever the key is in the ON position. A ground is applied to illuminate the lights.

I would use a solid state relay that is con*****ed by the LED lamp circuit at the front of the motor to close the relay so that a ground can be applied to the tachometer lights.

1.5 volts or so is used to turn on the LED's so you are going to need the appropriate relay that can be closed using that voltage. I would use a solid state relay to keep control circuit current to a minimum.

There is no wiring diagram that I am aware of that depicts this configuration.

[steersdad]

12 volt power is applied to the lights in the tachometer whenever the key is in the ON position. A ground is applied to illuminate the lights.

I would use a solid state relay that is con*****ed by the LED lamp circuit at the front of the motor to close the relay so that a ground can be applied to the tachometer lights.

1.5 volts or so is used to turn on the LED's so you are going to need the appropriate relay that can be closed using that voltage. I would use a solid state relay to keep control circuit current to a minimum.

There is no wiring diagram that I am aware of that depicts this configuration.

Gotcha. Understood. Thanks very much.

For about 20 years, I serviced German & Dutch made medical electronics. No schematics. Just basic "maps". And, all the wiring in Philips machines was red, and all the wiring in Siemens machines was yellow. That was a good education. This stuff is a piece of pie.
Thanks again