1975 85hp tach wire 12v?

[dodgeman67]

I am trying to hook up my the original two wire omc tach that came with my 1975 Starcraft super sport that had all the wires disconnected. Is the gray wire coming from the terminal strip always hot. I get 12v with the ignition off. I also get 12v from the strip on all the rectifier connections with switch off. Also the only connector that is there to connect to my gray wire has a green wire from the connector to the harness that goes to the controls. I am Leary of hooking it up as I don't want to burn up anything. Also, I tested the tach by connecting it directly to the third pole on the strip with motor running and it worked. Thanks

 

[boobie]

You may have a bad rectifier. Check that out first. Gray wire only has a signal when the motor is running.

 

[V153]

Gray wire only has a signal when the motor is running.

Correct.

Also when you key the ignition to the "on" position the tach should zero the needle.

 

[dodgeman67]

I will check the rectifier with the instructions in the sticky, What are the symptoms of a bad rectifier?

 

[V153]

What are the symptoms of a bad rectifier?

Well for starters your tach won't work right, or mebbe not at all.

And if the problem is unaddressed ya might just blow yer battery up?