1975 85 hp control unit gray wire purpose

[matthysone]

While trouble shooting an alarm problem in the control unit, which turned out to be an arm completing ground to the front of the buzzer when shifted into reverse, I found the gray wire disconnected coming from the wiring harness.
Someone else has wire nutted a wire to this gray wire but it dead ends to no where. Anybody know what this wire is for?

 

[wilde1j]

Re: 1975 85 hp control unit gray wire purpose

Grey is tach + pulse lead.

 

[matthysone]

Re: 1975 85 hp control unit gray wire purpose

Okay. Must have been a tach at some point during the life of this boat.
Thank you. Your reply is definitely appreciated.

 

[ScottinAZ]

Re: 1975 85 hp control unit gray wire purpose

Didnt neccisarily ever have a tach, but the controls came standard with the wiring option for one. My '75 50 horse controls have the same wire, and it has never been connected