1977 Merc 850 starter solenoid wire colors

[briankell]

Bought new starter solenoid, small posts marked with S and I. Old solenoid does not have marks. What post does yellow wire go to? S or I.

Thanks

Brian

[Laddies]

It sounds like you bought a auto solenoid with a ign. by pass wire the s is for the solenoid wire and the i goes to the ign. The reason the original was not marked is 1 terminal is for the solenoid wire and the other is for ground and it does not matter polarity. It might look the same but is not.

[briankell]

Laddies,
Appreciate the reply. New solenoid is Sierra part cross ref to original merc part. purchased thru local marine parts store. Solenoid is internal ground thru case to engine housing. According to seloc manual wiring diagram two small wires (yellow and black) go to key switch. Question should have been which wire (yellow or black attaches to S or I pole on new solenoid?

Thanks

Brian

[Laddies]

The original solenoid does not have a case ground, it has a black ground wire and a yellow energizer wire on the solenoid, the 2 small wires may be hooked to either terminal so the circurt is complete.

[briankell]

Laddies,

Appreciate the help and diagram. Obviously I had garnered some incorrect info from the "net" about the solenoid. Is ADI ignition synonamous as Thunderbolt ignition?

[Laddies]

Mercury used the Thunderbolt on all CD ign. systems whether battery powered or ADI.