'73 Merc 65HP - Positive or Negative ground?

[wp442]

Just getting started cleaning up and servicing the new-to-me '75 Glastron V-156 with a 65HP Mercury outboard. I've ordered the OEM shop manual (hasn't arrived yet) and am doing as much reading on this boat and engine as I can.

THIS WIRING DIAGRAM at maxrules.com seems to show that this motor is a positive ground setup. Is this correct or is the diagram mislabled?

 

[Steves69ss]

Re: '73 Merc 65HP - Positive or Negative ground?

I think its a negative ground....could be wrong....at least Im sure my 72 is a negative ground system...will double check tonight....Steve

 

[Chris1956]

Re: '73 Merc 65HP - Positive or Negative ground?

I think the poles on the battery are mislabeled on that diaghram. if you notice they have the red battery cable on the negative battery pole. Red is always positive.


Check your motor, and you will see that it is negative ground. The black negative cable from the battery is bolted to the lower cowling.

 

[wp442]

Re: '73 Merc 65HP - Positive or Negative ground?

Thanks for the info. I'm glad I asked first, before attempting to follow that diagram when hooking up the battery for the first time!