REV clock

brianwake

Cadet
Joined
Nov 23, 2007
Messages
15
Hello just bought a glastron GT 150 there is a rev clock in it from a mercury or a mariner 85HP. I am fitting a 85 Hp evinrude 1979 85995R would it be possible to wire it up? Thanks
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: REV clock

Yes. The older Merc and OMC tachometers (what you're calling a 'REV clock') are completely interchangeable. They both use the signal from the alternator (under the flywheel, used to charge the boat battery). Just run a wire from one of the alternator wires, where is connects to the rectifier. Make sure you have the tachometer wired to the 12V through the ignition key or you'll run your battery flat during the weeks you're not using the boat. Make sure the switch on the back of the tacho is set to the '12 POL' position.

Chris...........
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: REV clock

If you got the original control box with your motor, there's a 3-prong plug (might be covered with a rubber boot) right under the keyswitch, and a plug & play tach harness is available (got mine at BPS). if not, or you can't find the harness, just wire the tach 12V pin to the purple wire (keyswitch terminal A), the GND pin to black (keyswitch M), and there should be a gray wire in the engine wiring harness for the SND pin.
 

brianwake

Cadet
Joined
Nov 23, 2007
Messages
15
Re: REV clock

I don't have the original control box, I could not find where to connect the tachometer direct to the engine in the Manuel. Could any one help?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: REV clock

The tacho feed at the engine end is one of the stator wires on the rectifier. You'll find that there are a couple of wires (usually yellow, but not always) coming from under the flywheel. These two wires run to a terminal strip then to a round metal device, usually with a third wire, red. This is the rectifier. Connect a wire to either one of the wires from under the flywheel and this will run your tacho.

Chris............
 
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