1986 Merc, start and trim problems

ab59

Ensign
Joined
May 10, 2017
Messages
979
I put this motor on the boat and started hooking things up. I could start it fine but could not get the trim to actuate from the controller. I changed the position of the wires at the solenoids and got it to work but it was a little weak current wise. I ran it down to a stop and now I can't start it or trim the motor up unless I just either one at the motor. This short video will explain the problem. A little windy today so you may want to turn the sound down a little. Is there a fuse in the controller somewhere?

 

ab59

Ensign
Joined
May 10, 2017
Messages
979
Well, I found the fuse that was burned and I can start the motor now and operate the trim. However, this does not tell me why I burned the fuse, to begin with. Cannot see any problems upon visual inspection but my eyes are not so good anymore so I could be missing something easy or obvious to someone who has experience with these trim systems.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,108
Likely a power wire rubbed against a ground wire, and blew the fuse. Check the insulation where it exits the cowling and enters the control. PTT wires often wrap around the control throttle handle pivot. They can wear there.
 

ab59

Ensign
Joined
May 10, 2017
Messages
979
Since I have made this video, I have replaced the solenoids and still can not get the trim to actuate when the wires are connected to the small terminals on the solenoids. When hooked to the main posts on the up and down solenoids the switch at the controls works just fine but seems like it is not getting full power to the trim motor. This is how I burned the fuse that knocked out the starter as well. Once the fuse was replaced and the wires hook to the large terminals, the trim will work but will blow the fuse again if I continue to use it this way. I am using the same hot lead when attaching the wires to the small and large terminals. I don't know what to do from here to fix this problem or even where to look next.

 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,103
Well,.... This alittle outa my league,.... But,......

Yer trim switch, should have 3 wires, blue(up), green(down), 'n red, battery power,.....
When pushed, the switch powers the blue, or green wires,.....
Do you have power at those blue, or green wires at the solenoids,..??
Are those solenoids supposed to have ground connections on the other tiny terminals,..??
Do you have a test light,..??

My guess is, yer blowin' that fuse, because the trim power is goin' the length of the boat twice, runnin' through the switch, insteada gettin' power through the solenoids,....
It's to far, through to tiny of wires, causin' resistance, which blows the fuse,....
 

ab59

Ensign
Joined
May 10, 2017
Messages
979
Well,.... This alittle outa my league,.... But,......

Yer trim switch, should have 3 wires, blue(up), green(down), 'n red, battery power,.....
When pushed, the switch powers the blue, or green wires,.....
Do you have power at those blue, or green wires at the solenoids,..??
Are those solenoids supposed to have ground connections on the other tiny terminals,..??
Do you have a test light,..??

My guess is, yer blowin' that fuse, because the trim power is goin' the length of the boat twice, runnin' through the switch, insteada gettin' power through the solenoids,....
It's to far, through to tiny of wires, causin' resistance, which blows the fuse,....
Thanks for your reply. I have the red wire coming from the switch ( fused ) connected to the positive on the up solenoid where the positive wire ties both the upper and lower solenoids together. I am thinking that since I get power to the trim unit when hooked up to the large terminals that the three wires coming from the switch have power. When I connected the blue and green wires respectively to the small terminals I am not moving the positive connection so I think I have power to the solenoids. Right? The grounds would be the same, Right? Do I have the positive from the switch connected to the wrong place?
 

ab59

Ensign
Joined
May 10, 2017
Messages
979
I have solved the problem through research on the internet and a random picture of a set of solenoids. A simple solution to weeks of asking. The PO did not restore the grounds to the small posts on the solenoids. A picture on the internet showed how the wires were supposed to be connected. After making a couple of ground wires and hooking up the respective green and blue wires to their solenoids on the small posts, then grounding both solenoids at the second small post, the trim now works as it should.
 
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