Trim help..89 Celebrity Mercruiser 3.0

Danzalon

Cadet
Joined
Jul 6, 2017
Messages
6
Mercruiser 3.0 sterndrive
Last time out the trim malfunctioned during my time on the lake. Worked fine at launch.
Trim goes down, but not up. I can fortunately bring it up with the throttle. Any suggestions would be appreciated.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,398
. I can fortunately bring it up with the throttle

Howdy

Can you clarify how your bringing the drive up with the throttle?
Also what year is the boat?
 

interalian

Commander
Joined
Jul 23, 2009
Messages
2,105
Trim limit switch or associated wiring. Been through that on a 3.0 just last week. Used the trailer to trim during lake trials, but that's risky on the u-joints from what I've heard should you over-trim it.
 

Danzalon

Cadet
Joined
Jul 6, 2017
Messages
6
Can you clarify more? Trim limit switch wiring in the handle? Does solenoid have to be replaced or being that it comes up using the trailer it's ok? What did you do to fix exactly?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,398
The drive should not be trimmed up more then the trim limit position with the motor running. If your using the trailer switch the drive can be brought up past the limit. While running at low speed or high I don't see you going above this limit because the boat will be porpoising and/or the nose of the boat will be very high. So the only time you might get it to high is when idling.

The fix you probably have a bad trim limit switch. The switch is on the port side of the gimbal ring. The switch is adjusted so the regular trim switch allows for normal trimming until the limit is reached. When the limit is reached the switch breaks connection so the drive comes up no further. This switch is bypassed by the trailer switch. The drive limit switch is item h in the pic
Trim wiring Merc 2012.jpg
 
Last edited:

Danzalon

Cadet
Joined
Jul 6, 2017
Messages
6
I took it out and the trim started working up again. But then later stopped working and I had to use the trailer switch. Would a bad limit switch do this or would it not work at all if it was bad? Just wondering if I should look into anything else since it worked again for a period of time.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,398
I took it out and the trim started working up again. But then later stopped working and I had to use the trailer switch. Would a bad limit switch do this or would it not work at all if it was bad? Just wondering if I should look into anything else since it worked again for a period of time.

The limit switch can work and stop working, it just two contacts. Get a little corrosion on it and it will be on/off/on/off etc
 

Danzalon

Cadet
Joined
Jul 6, 2017
Messages
6
Thanks, AllDodge. Do you recommend have it replaced, or is there something to minimize the cost and repair. The swap out I saw on line looked to involve disassembling the back to just get at it.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,398
If you want it to work as designed then yes you want to replace it. If your OK with it working but without a limit, then connect the purple/white and blue/white wires together with a jumper. Doing this will turn your trim up switch a trailer switch (so to speak). If later during other work it can be replaced then.

Another option, which is not recommend because of corrosion, is cut the wires going to the switch on the outside at the switch. Then splice in a new switch and reinstall.
 

Danzalon

Cadet
Joined
Jul 6, 2017
Messages
6
Ok. Now I have a new topic. I took both trim switch and trailer switch's off and cleaned them. The trim now appeared working UP now. But when i was on the lake the trim gage was going hay wire. When the trim switch was initiated down all the way on the gage it hopped all the way over to the "up" on the gage and stayed. I cant determine the limit and gage.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,398
Your trim sender also needs replaced. Its on the starboard side and is a variable resistor.
 

interalian

Commander
Joined
Jul 23, 2009
Messages
2,105
If you want it to work as designed then yes you want to replace it. If your OK with it working but without a limit, then connect the purple/white and blue/white wires together with a jumper. Doing this will turn your trim up switch a trailer switch (so to speak). If later during other work it can be replaced then.

Another option, which is not recommend because of corrosion, is cut the wires going to the switch on the outside at the switch. Then splice in a new switch and reinstall.

If you were to use glue-lined heat shrink tubing over a soldered splice, you'd stand a pretty good chance of a durable connection. I'd do that were it mine (and likely will be on my neighbor's bateau).
 
Top