MPrimeaux
Petty Officer 1st Class
- Joined
- May 10, 2019
- Messages
- 240
Ok everyone, I'm a little stumped and was hoping someone could point me in the right direction. I have a 1978 Mercury 500 with the old transom mounted, external power trim pump. Uses 2 cylinders, 4 hoses, has the rectangle reservoir, One solenoid, and two button trim switches. I bought a replacement pump motor and reservoir because mine was starting to drag pretty bad. A tap or two from a hammer would get it going again for a few seconds... but it needed to be replaced. The original pump motor had 2 wires (green and blue. had an additional black wire going from motor case to the "I" terminal on the solenoid) and the new one has 3... Black, Green, and Blue. I wired it up with the black wire landed on the "I" terminal, the green on the terminal with the green wire from the "down" trim button and the blue on the main terminal of the solenoid. Had to run an external ground to the frame of the solenoid to ground the coil due to the replacement reservoir being plastic. Works fine with the down button, but with the UP button the motor does run and runs in the opposite direction, but the solenoid latches and won't release until I pull the + or - off of the battery. If i just jump power from the battery straight to the solenoid coil it works energizes and de-energizes correctly. It only latches when you use the up trim button. What in the world is causing this?? Any ideas?