73 merc 1150 power trim help

the top button on my power trim doesn't work for trailer mode. I've chased the wires and found no problems which leads me to believe it has a bad trim limit switch, my question is if there is a way to bypass the trim limit switch and if so how?

Re: 73 merc 1150 power trim help

OK - You have the three button trim control correct? If so, the middle button trims the motor, and uses the trim limit switch. To tilt the motor up for trailering, you push top and middle buttons together.

To bypass the trim limit switch, simply disconnect it where it joins the PTT harness, near the trim pump and put a jumper betwen the connectors.

Re: 73 merc 1150 power trim help

Thank You for your reply, this forum and all you guys are incredible with your help and hopefully I'll be able to return the favors with some help someday.
But anyways can you give me any more info on bypassing the trim limit switch. I tried jumping about every which way could be and nothing worked.
My power trim wires don't hook into the main motor harness they are on their own. There is only two wires that go to the limit switch, one blue and one purple, they have plug in connectors before they go there. I would have the switch fixed but as far as I can see you have to pull the motor to get at it.
I'm trying to get this in the water before summer is over so I don't want to take this on until after summer, but in the same sentence I hate things that don't work. I would like to get the motor up higher for transom saver for trailering. So as far as to what I have done I have jumped wires every which way and nothing bypassed that switch, it either worked the same and stopped half way or didn't work at all. This is a boat I am rehabbing, total remodel, basically my first one to this depth, and is also my first one with power trim so I am a little baffled. Any futher help would be appreciated(which wires do I jump?At which point do I jump them?how about he wires at the switch?the blue wire also hooks to a bolt some kind of valve on the pump motor itself, is this a switch of some kind?)
Again any help would be appreciated and thank you for your time and knowledge.

Re: 73 merc 1150 power trim help

Well it sounds like your PT wiring is a bit messed up. However, the system is pretty simple. The harness runs from the 3 button panel to a 3 connector plug on the PTT pump. Near the pump there are two bullet connectors. These need to be jumpered together, to bypass the trim limit switch.

BTW, if you remove just the PTT bracket on the starboard side of the motor (s/b a transom bolt and a thru bolt for the trim cylinder, plus a 1/2 fine thread bolt into the transom clamp, and maybe a threaded rod also), the trim limit switch can be removed. Trace the black wire (looks like a hydraulic line)from the starboard trim bracket to the PTT wiring harness, if you can. Those are the two wires to unplug and jumper the harness together.

Re: 73 merc 1150 power trim help

sorry for the delayed response I over tightened a bolt and the pump was off to the machine shop, but it is in now working great and I bypassed the switch just like you said so my motor now goes all the way up.
Thank You So much for your help