1980 Mercruiser Trim Wiring

[ivianiac]

Sorry I posted the wrong year in my other post it is a 1980 Mercruiser 350.

I finally have the motor running. Thanks again to everyones help.

Now I can't seem to find the appropriate wiring diagram for my trim motor.

I have 1 solenoid. The motor has a Blue, White and Black wire comming from it. That doesn't match any of the schematics I've found.

From the control I have a Red, Blue/White, and Green/White.

When the wires come back from the control they plug into a socket and kind of dissapear (I'm tempted to hard wire the wires if I can find out where they go), I can see a red wire from the side that bolts onto the relay. I can not tell where the other wires go and where I am suppose to connect them.

Attached is a couple of photos.




Also any other tips for freeing a steering cable? I have heated it wiggled it all over but it still doesn't want to move. I sprayed it with lube and left it for the night hoping the lube will work it's way in.

I'm so close to getting my boat ready to run. Trim wiring, Steering cable and Throttle cable and I am set to go.

 

[Bt Doctur]

Re: 1980 Mercruiser Trim Wiring

on the motor : blue-sky-up, green(in your case white) -grass-down
the small red wire gets power from the solenoid, blue/white wire is used to activate solenoid in the"up " mode. green/white connects to motors "down" lead or white wire at the plastic junction block

 

[ivianiac]

Re: 1980 Mercruiser Trim Wiring

Thank you very much. The sky/ground thing helps a lot. Is this solenoid different than a solenoid on a winch? do you know which posts serve which function on the solenoid?

 

[Bt Doctur]

Re: 1980 Mercruiser Trim Wiring

most of the solenoids we use are called isolated base. that means you must supply both power and ground for it to work.
in your pic, the large post on the left is main battery power ,the large post on the right is trim up.
the small blue wire comes from the control box trim switch and triggers the solenoid, the small black on the right is the ground wire making it work.

 

[ivianiac]

Re: 1980 Mercruiser Trim Wiring

Does the solenoid connect the right or 4th post to the mid-right or 3rd post when the solenoid is at rest?

Then when the 2nd post gets power does it connect the 1st and 4th posts?

If that is the case how does the white wire from the motor get grounded?

Sorry for my trouble in understanding how this relay operates. I'm tempted to just install a relay from a winch

Perhaps I am understanding the pump incorrectly? Is this correct: To operate one direction (up) the pump wants +12v to blue and ground to white. To operate in reverse the pump wants +12v to white and ground to blue?

 

[ivianiac]

Re: 1980 Mercruiser Trim Wiring

I think I may have just figured out what I am missing.

The two wires are not actually reversing they are both just using the black ground from the motor?

So I need to only provide +12v to the Blue to go up and ground to the black

Or provide +12v to the white and ground to the black to go down.

If that's the case then I think I finally get this!

 

[Bt Doctur]

Re: 1980 Mercruiser Trim Wiring

you would be correct

 

[ivianiac]

Re: 1980 Mercruiser Trim Wiring

Thank you so much. I can't wait to get home, I should finally be able to operate my trim motor

Why can the control 12V work for the down but a solenoid is required for up? If I find my solenoid is bad could the 12V that is returned from the control operate the up?

 

[Bt Doctur]

Re: 1980 Mercruiser Trim Wiring

when going foward the motor will draw hi currect from trying to pump the drive outward under load. coming down in gear is like no load and draws much less current. Most of us have rewired it to have 2 relays like the newer pumps.cuts down on the current traveling the trim cable to the pump.

 

[ivianiac]

Re: 1980 Mercruiser Trim Wiring

Well I think my pump is shot

This is what I did.

I disconnected the pumps blue and white wires from the block and solenoid. I cleaned up the black wire connections and connected it to ground (negative).

I then applied +12V DC directly to the White wire going into the motor. The pump didn't run.
I applied +12V DC directly to the Blue wire going into the motor. Still didn't run.

When I kept digging I noticed I am getting a +12V reading on the wire that is not connected (while connected to White the Blue was hot and visa versa)

I assume this means the pump has a short internally?

 

[Bt Doctur]

Re: 1980 Mercruiser Trim Wiring

http://www.boatfix.com/merc/Servmanl/6/6C5R3.PDF