1979 Mercury Trim Motor End Cap

[dcr1962]

I tried to lower my 115 Mercury for the first time. No noise from the pump motor but I had good battery. I removed the motor end cap and the black wire isn't connected to anything. Does anyone know where on the cap it should connect? I believe it is the 3 wire Prestolite ERH4102.

 

[Chris1956]

Re: 1979 Mercury Trim Motor End Cap

The motor needs to have the black wire grounded, in order to function.

 

[dcr1962]

Re: 1979 Mercury Trim Motor End Cap

I don't mean the wire outside the motor, I mean the wire internal.

 

[Chris1956]

Re: 1979 Mercury Trim Motor End Cap

The trim motor has two sets of windings. The ground wire (black) is common to both. If you disconnect all three motor wires (green, blue and black) and put an ohm meter across the black and green and black and blue, you should have continuity. There should be no continuity to the motor casing.

There is a bimetal thermal circuit breaker inside the motor. Sometimes these open and either do not close, or get some junk in the points causing an open in the circuit.