Mercuiser 140hpTrailer switch

hey can anyone tell me where the trailering switch would be located on my assumed 1977 mercruiser 140 3.0L. I need to do a test but i have no clue where that switch is located please help ASAP

Re: Mercuiser 140hpTrailer switch

you need to get service manual #2. kiind of a poor excuse for a link but it's the best i've seen. ya can buy it from mercruiser too. anyways, it has all that info in it.
do you mean the trim limit switch?
or
trim sender?
or are ya referring to the control on the dash. i assume a three button set up. if so, the bottom button is in/down. the middle button is trim up/out. ya use the middle button + the top button for trailer function. these two buttons together raise the drive to it's fullest extent. using the trim only button raises the drive but the limit switch mounted on the bottom of the middle of the gimble ring, actuated by the bell housing, limits trim to only up/out so far. so ya don't damage things by raising it to far up/out.

Re: Mercuiser 140hpTrailer switch

ok Thanks ziggy i was getting confused because it sounded like there was a switch for trailering the boat somewhere around the stern of the boat so i was seeing if that would work based of what people told me about the top two switches not working for the trim.
Thanks for clarifying things for me now i just got to get the motor to trim up

Re: Mercuiser 140hpTrailer switch

typically on our old boats w/ mc-1 drives. the trim limit switch fails. so the middle only button don't work. however if ya use the trailer function. using the top two buttons together, the drive will raise. in trailer mode the failed trim limit switch is bypassed. you can raise the drive as far as ya want. my limit switch has failed. i just use the trailer function, w/judgment. ya don't want to get the drive trimmed so far up it's outside the gimble ring supports. they support side to side motion of the drive.
ya can also jump a wire inside the boat by passing the trim limit switch if it's failed. achris has the attachment for ya, i'll let him get onto that. i seen him around lately.

to find the trim limit switch. follow the groove worn into your bell housing, dead center disappearing behind the gimble ring. if yours is like mine, the switch will be wearing on the bell housing.

edit, if the trim limit switch has failed. best i know, it's a nla part, hence the reason for doing it like i do (using trailer function for trim) or using achris' bypass.

Re: Mercuiser 140hpTrailer switch

I have for about 15 years had a 'transom mounted trim switch' on (surprisingly enough) the transom of my boat. It offers fantastic convenience for tilting the drive up and down without having to climb into the boat every time.... Installation is really easy, just a 3/4" hole with a screw hole either side (box comes with a drilling template).. Electrical connection is even easier, just pull the plug out of the trim pump (that goes to the control buttons up front), plug the harness from the new switch in and plug the old connector into the other plug on the new harness. With a coffee break in the middle it takes about 20 minutes to do, and then you'll wonder how you ever lived without it.

Just one small trap... There are now 2 different variants. One for the older connectors, with the round 3 blade connector, and one for the new style 'Packard' connector...

Here's the part number for one of them, but I don't know which one. As I'm not at home I can't check my manuals, which I know I have the numbers written in.

87-815200A02

HTH,

Chris........

Re: Mercuiser 140hpTrailer switch

ok so you use both buttons on the top to access the trailer bypass

Re: Mercuiser 140hpTrailer switch

yes, the middle button + the top button. using these buttons bypasses the trim limit switch.
or
i found what i wanted after a little looking through the book marks.
trim limit switch bypass, post #3 (the post by achris).

Re: Mercuiser 140hpTrailer switch

Thanks chris i was typing at the same time as you and never saw your post but unfortunately mine does not have that and i think im going to have to replace the trim switch on the dash as to it only works in down and i have no clue how to bypass the trim cutoff switch and it wont go up so if its in my budget i will just see how much both will cost

Re: Mercuiser 140hpTrailer switch

thanks ziggy i tried that but i will have to play some more i was only out there for a few minutes because it is pouring, any ways it didnt work that i could tell but like i said it was pouring so will try when my 40 days of rain are over. (p.s. how bad is it if my unglassed plywood floor gets soaked b4 i glass it, i would have to either replace it or hope it dries will quick right?)

Re: Mercuiser 140hpTrailer switch

ya need to get s/m #2. it has a trouble shooting guide for won't trim up/out. in that link i gave ya, go look at pp 10-55. if ya can.

Re: Mercuiser 140hpTrailer switch

i was just doing that i think will see what the wires look like as long as i know the pump runs. now my guts not turning any more over replacing the 300 dollar part (half of what i paid for the boat)

Re: Mercuiser 140hpTrailer switch

well i tried using the trailer function to no avail but i realized that when i press in/out button the lights dim meaning its using power but the trim limit switch is stopping it but nothing happens at all when i just press the up button so it needs replacing right?