Re: 1977 internal 2 wire trim motor has broken wire - fixable?
How close to the motor is the break rg? If you have the length, butt splice it back together and follow up with a double layer of heat shrink with sealant.
If the break is in the grommet entering the motor, maybe all you need to do is remove the grommet for a fix.
The two screw on top of the motor usually hold the motor to the top of the reservoir. If you need to remove the motor, I would suggest draining the reservoir first.
And as usual, a good service manual would help. If you would give the model number, we might be able to find out if the cap with the brush and lead assembly is still available.