Help-trim problem

[thundercraft260]

my boat 92 thundercraft 260 express 5.7 merc bravo-2
the boat was working fine until the end of the day, then all of a sudden I could not trim up my drive unit. It will trim down no problem, but to trim up it will only work using the trailer trim. I had the pivot pin,gimball,bellows & etc repaired/replaced last month. So the whole assy was appart...Can it be the limit switch & if it is do I have to remove the boat from the water to repair/replace it or is it sealed and won't leak...? Is there a connection in the bilge as I was fumbling around changing the oil the day previously, could I have loosened a connection and id so why only the trim up position?

Thanks for your help....going on vacation with her next week

John

 

[dniez45]

Re: Help-trim problem

Probably the trim limit switch, either out of adjustment, defective or a broken wire. The switch is tied directly into the pump unit. The switch is located on the port side of the gimbal ring and the Trim Position is on the starboard side. You can disassemble the switch, remove the cover and view the contacts. You could clean them up with some WD-40 using a small stiff artist brush, blow that out with air, then do the same with some de-natured alchohol. Then try it out. It may also be that you happen to be above the limit area already because you've raised it at some point in time with the trailer switch. Lower it back down to get within the operating range of the switch. If that does not work, then check for a broken wire between the switch and the pump. The trailer switch basically bypasses the limit, that's why it works. If this doesn't work, then you must replace the switch.

 

[rbh]

Re: Help-trim problem

oh yeah,
on our mercruiser there is the wires coming through the bellows. one is to the pump for the leg limit.the other is for the trim gauge
if the wires for the leg limit are unpluged nothing will work.
rob

 

[thundercraft260]

Re: Help-trim problem

update...
Thanks for the help. I found a trouble shooting bulletin from another post, got it down to the limit switch (all connections were good). Can anybody tell me or post how to replace it. I assume the boat has to come out of the water, leaving on vacation in 3 days, any help is greatly appreciated.

Thanks
John

 

[picklenjim]

Re: Help-trim problem

If all you are doing is replacing the limit switch and not the wires it's easy.It's located on the port side of the gimble ring.Just remove the 2 screws and turn it upside down and disconnect the 2 wires.Connect the wires to the new switch.Look at the bottom of switch and on the hex shaped shaft coming out you will see a small line on the end.Also on the bottom of the switch you will see a small line.Turn the shaft so the lines are lined up.Now with the drive all the way down put the switch back on the gimble ring with the screws as close as possible to the center of the slots their in without turning the hex shaft in the switch.Leave the screws a little loose.Have someone hold the UP switch. As the drive raises turn the switch in the slots so it stop when the drive is about to come out of the guides at the bottom of the gimble ring.Tighten the screws.From this point you will need to use the trailer button to raise the drive the rest of the way.

Actually these switches are very simple. You may want to take yours apart and clean it up,sand the contacts a little,put it back together and try it.Lot of times thats all it needs.

Another thing you may want to try first is just loosen the screws some.With the drive all the way down have someone hold the UP switch while you turn the limit switch back and forth in the slots and see if it starts to run up.Sometimes that will clean the contacts and make it start working right.

If all fails don't sweat it. You can always use the trailer button while on vacation and fix it when you get home. Good Luck