Trim/Tilt question

[SHickey]

Hello,

I am slowing making progress on a '74 21' Mirrocraft I picked up this spring. It has a Merc 140 3.0 and a MC-1 outdrive. I got the engine finally running after unsticking a valve and readjusting the lifters.

Now for the Trim/Tilt, I replaced the only solenoid attached to the pump motor and followed the wiring diagram for units that have only one solenoid. Unfortunately the unit only goes up. I have a three button trim tilt unit and when I press the dn button the unit goes up, press the up button and the unit does nothing, press the middle button, nothing happens, and just for kicks, if I press the up and dn button together the unit goes up.

My question is whether or not I am missing a solenoid for the dn operation?? I am aware that some of these old units did have only one solenoid and when the pump motor runs, it is very quiet and slow but effective (for not being used in 2 years or more) Not like the trim tilt I have on my '76 Merc 165 that has two solenoids and you can really hear the pump working up or down.

If this unit only has one solenoid, does someone have a diagram of how the solenoid and the pump is wired so that I can double check the wiring and if someone believes I could install another solenoid to this pump, I can repeat the wiring model from my 165 and use it to rewire this older unit, if that makes sense.

If I can get this thing to work up and down then the next step will be to replace the outdrive prop shaft seal. So much fun working on old tin cans!!

Enjoy

 

[Bt Doctur]

the up circuit goes thru the solenoid because going up uses more current. the down circuit is the green motor wire wired to the green wire coming back from the 3 button control.

 

[Bt Doctur]

 

[SHickey]

Thank you Bt Doctur for your response.

I will double check the wiring on my unit and hopefully there is something amiss.

If in fact the wiring is correct, do you have any other remedies that can resolve the dn issue and is there any valve or release on the unit that I can open to manually bring the unit back down?

And lastly, does the pump motor rotate one way for up and the opposite way for going dn??

Have an enjoyable Tuesday everyone!!

 

[Bondo]

If in fact the wiring is correct, do you have any other remedies that can resolve the dn issue and is there any valve or release on the unit that I can open to manually bring the unit back down?

And lastly, does the pump motor rotate one way for up and the opposite way for going dn??

Ayuh,..... The only way to lower the drive is to crack the lines, 'n bleed the oil off,.....

Yes, the motor polarity is reversed, by the switches,,...

 

[SHickey]

Thank you Bondo for your response.

I was hoping I could lower the unit manually so that if I keep testing the unit and if it just goes up, I am fearful it may get stuck in the up position.

Could you tell me which line I would need to disconnect to lower the unit manually if it becomes necessary??

And lastly, could you give me a loose estimate for the cast of replacing a prop shaft seal for an MC-1 lower unit?

Thanks again