OK, I’m lost, don’t understand what you are describing…
How many wires does the trim motor have coming out of it, two or three?
Three wire motor: The black lead is always grounded. The blue lead is connected to battery positive (green lead not connected to anything) to make the trim motor run in the "UP" mode. The green lead is connected to battery positive (blue lead not connected to anything) to make the trim motor run in the "down" mode (opposite direction).
Two wire motor: Green lead is grounded and blue lead connected to battery positive to run the unit in the "up" mode. To run in down mode, blue lead is grounded and green lead is connected to battery positive.
Both of these types of trim motors require separate trim/tilt junction box harness in 1980. The junction box/harness for the three lead motor is completely different (just one conventional solenoid) from the two lead motor junction box/harness which had two relays in the box.
You can not connect either of these systems through the starter motor solenoid or you will be in trouble.
Post pictures of what you have if that will help….

I believe the relays flip polarity is all. One for trim up/down & The other is for tilt up/down. You need to locate the correct pair, then reverse the pos/neg polarity. The motors are different too. The first motor is double wound for both directions & the later motor is single would, I believe. I have never been inside this set up but it is the logical way to wire a reversing motor. Later they learned with a DC motor it can be reversed inverting the inputs using direct current.

Again, I am confused. Does your tilt motor have two or three leads? You will make a mess, damage stuff if you try to adapt the two relay trim/tilt junction box/harness to the three wire tilt motor.
PS You can email me the pictures if you like, I will post them: Don

• This reply was modified 6 years ago by fleetwin.
• This reply was modified 4 years, 11 months ago by seakaye12.

Yes,
E-mail to Don the photos as he has the drawings. Two relays is all you need to reverse the motor. One motor has three leads, the first is the common return to the battery, The second & third wires run the motor clockwise then counter clockwise. Then the next relay energizes the second function like up & down. You wouldn’t hurt the actual pumps as they are made to reverse. Next the hydraulic cylinders have two ways of building them. They can be single or double acting cylinders. The single acting cylinder has one port for pressure which pumps fluid to raise the motor. Going down it uses the weight of the motor & no fluid is pumped. It operates by the weight of the motor & opens a solenoid valve that opens & returns the compressed fluid back to the reservoir. The double acting cylinder opens two ports on the cylinder & one side of the piston gets filled by the pump & the other side of the piston gets evacuated back to the reservoir. this makes the cylinder change directions. Reverse that & the cylinder changes direction. There is more to it but that is the basic operation. Now if you connected the up & down wires to the battery thru the solenoid it would not be good on the relay or the pump motor. You may of caused a dead head too where the pump is running trying to move fluid & no ports were opened.
Hope this helps & THANK YOU DON for your help!! Don would you send me a drawing so I can learn too?
God bless you! Jeff.50@cox.net.

I’m so sorry about the relays. There are different relays too. Is the relay normally closed or normally open with no battery power. Also they are wired to reverse the polarity on the output, not just close as in single acting. That too includes the hydraulic valving, some port normally open or closed. Then comes the third setting using the hydraulic porting where they snap closed. If it doesn’t snap closed it will become sloppy & not hold position.