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Tach not working

Jerryjerry05

Outstanding Contributor
1986 200 Mercury
The wiring in the boat was a big ol pile of spaghetti!!
I finally got all the wires back to where they were supposed to go( I think :) )
How do you check the motor to see if the signal to the tach is working?
I turn the key and the digital readout (bottom face of the tach)comes on but when it's running the tach doesn't work.
The lights in all the instruments comes on when the lights are turned on.
THANKS!!!
ANY HELP!!
 
One of the two yellow wires coming from the stator, for charging the battery, also operates the tach. Try one and, if it doesn't work correctly, try the other one.

Jeff
 
Try what? More detail if possible

Thought the grey lead fed the signal to the tach?

I have a DVA meter, if that helps.

I've not done this before???
Thanks.
 
The tach needs a + and - connection and a connection to one of the yellow wires on the rectifier, open the cowling and look for the rectifier/regulator and note the color of the signal wire that comes off it (in the diagram it's brown yours might be different), trace this wire to the tach and hook it up to the sender terminal on the tach. If you have to run a new wire for the sender that might simplify your problem. (Note: the diagram is for an older motor but the method is the same.)wiringhipower767778.jpg
 
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