Trim limit switch

[Sosebee88]

Okay guys, very new to most of this. 1994 caravelle bow rider 1750. Mercruiser 3.0 (s/n F424546) alpha one gen 2( s/n 0f468056). Messing with the trim limit switch. A diagram I found shows only one limit switch, mine has two(seems common to me). I just recently got the boat. Port limit switch is connected at the trim pump. Starboard limit switch is not connect nor do I see any wires it could. Port side is connected to a purple and blue at pump. Any ideas where the next set of bullet connectors will be for starboard side limit?

 

[Bt Doctur]

Most 3.0`s use a dummy with no wiring for the trim gauge ,just the trim limit one.is wired. If you do have a trim gauge then the wire could have rotted of or were cut off

 

[Sosebee88]

There are two round limit switches on the side of the stern drive, both with wires through the transom. Only the port side is connected to the wires near the pump. Are you saying it may only use one of those switches?

 

[Bt Doctur]

Do you have a trim gauge in the dash?

 

[Sosebee88]

Yes there is a gauge. As far as the previous owner and I know it's hasn't worked. It would not trim up unless using the trailer button. I'm still assuming one of the wires or switches is bad or damaged. But the starboard switch is tricking me.

 

[Bt Doctur]

see page 5A-34 http://www.boatfix.com/merc/Servmanl/6/6A5R3.PDF

See if any wires are connected at the gauge and what color they are

 

[Bt Doctur]

see page 4E-2 http://www.boatfix.com/merc/Servmanl/13/13E4R2.PDF

 

[Bt Doctur]

If the trim up is not working but the trailer function is working to raise the drive then the trim limit went bad and was bypassed

 

[Sosebee88]

that last page helps very much. There is a brown wire with a bullet that is not being used. Very much appreciated sir.

 

[stonyloam]

Port is trim limit, starboard is trim gauge. Sounds like your trim limit switch circuit is bad (either wires or switch). If the trim does not work but the trailer does it has not been bypassed. So go the stern, locate two black wires coming through the transom from the trim limit. They should be plugged into two connectors, one with a purple/white wire and one with two blue / white wires. Unplug the black wires and with a short piece of wire jumper between the connnectors. Try the trim. If it works you know the trim limit is bad. Your trim switch will work, but there will be no limit.

 

[Sosebee88]

Thank you stonyloam, I went back at it today and realize what you just said about the two different switches. The limit switch is in fact still good and after some adjusting I can now trim up and it will stop with the limit switch. I found the wiring for the gauge to be bad and touching each other. I repaired and re covered the wiring but I believe the gauge switch(at stern) was seized and it broke the tab that should rotate. After replacing the down/in solenoid I now have a functioning trim system but no gauge. Thanks again guys.

 

[stonyloam]

My gauge has not worked for 20 years LOL! You will learn to trim the boat by feel and tachometer. As a general rule you will start out trimmed down, then when you come up on plain, trim up till it just starts to porpoise a bit then trim down till it smooths out. Watch the tach, your most efficient trim will give you the highest rpm at any given throttle setting. You should be retrimming any time something changes (speed, direction to waves or somebody moves). After a little while you will find you do not need the gauge and never miss it.