Trim Gauge

[Slippery When Wet]

Well, I finally splashed my boat today. Fired right up and everything seemed good. I put it into reverse and went to back away from the dock and it wouldn't move...I then realized I forgot to put the drive down, it was nearly all the way up in the "trailer" position. I put the drive down and all seemed OK...I know this is not good for the U-Joints, but everything seemed OK....whew. Then I realized my trim gauge was whacked. It was reading erratically, it would not go all the way down even when the drive itself was. It would jump all over the place when adjusting the trim. I took the boat for a little cruise and I know the trim is working properly, just not the gauge. Once I got to the slip, I shut it down and turned the batteries off, hoping that may "reset" it. No such luck.

My questions:

1. Could me trying to operate the boat with the trim all the way up have screwed something up? Seems unlikely, but the gauge worked fine when I put it away last fall.
2. Is it likely the gauge or the sending unit?

Any opinions/suggestions would be greatly appreciated.

Thanks!

 

[annie]

Sender unit.. These things are renown for giving trouble. Lots of posts about this on here.
You can't damage sender by operating leg full up.
The other cheaper thing to check is the earth and sender connection to the gauge?

 

[Quint4]

the engineering of the trim senders is crap. I put brand new ones on a few seasons ago and they still did not work right ( I did it right.....no wire splicing). I am now happily over them. I don't need them. Sorry for not being much help but that is my perspective.

 

[Slippery When Wet]

Sender unit.. These things are renown for giving trouble. Lots of posts about this on here.
You can't damage sender by operating leg full up.
The other cheaper thing to check is the earth and sender connection to the gauge?

Thanks for confirming what I suspected. Bad ground does seem likely based on the symptoms.

the engineering of the trim senders is crap. I put brand new ones on a few seasons ago and they still did not work right ( I did it right.....no wire splicing). I am now happily over them. I don't need them. Sorry for not being much help but that is my perspective.

yeah, I really don't need it as I know where my trim is. I usually run with it nearly all the way down and trim up a bit at higher speeds. I have trim tabs for controlling bow rise. I am just a little anal retentive about everything working right and I'll probably sell this boat in a year or 2 and will want everything working properly when I do.

 

[Slippery When Wet]

OK, next question...I have never worked on a trim system. How difficult is it to figure out where the sender is and how to check the grounds?

Thanks!

 

[annie]

Have a quick look at the sender unit wires.... They usually break at the sender unit (stbd side of leg)
Agree with Quint.... New ones made in Mexico...

 

[Quint4]

The senders/switches are the "hockey pucks" on the side of your outdrive. The Trim Limit Switch is mounted on the port side and the Trim Position Switch is mounted on the starboard side.

 

[Slippery When Wet]

The senders/switches are the "hockey pucks" on the side of your outdrive. The Trim Limit Switch is mounted on the port side and the Trim Position Switch is mounted on the starboard side.

Oh great, so I have to pull the boat out of the water to check these? Or are the potentially faulty wires inside?

 

[Ka1oxd]

I never dealt with a merc out drive, but I did the one on my OMC. I agree with the others, pull it out and replace it, do not splice the wires, not worth it.

 

[mwph]

I don't have the hands on experience that Quint and these guys do, but after studying the system & tracking down the problem on my own boat, I agree, the design is crap. You will have to pull the boat if you want to do anything other than test the gauge, the actual switches or the wireing back to the transom.

You did not mention that the drive was off the boat or worked on during the off season. That would be a huge factor if it was. In my case, the drive was off, worked on & replaced. I have come to the conclusion that the way the wires come out of the unit & are fed through the housing, they can not take the abuse that my marina mechanics dished out.

The possibility of a wire failure due to damage or a bad ground is always there but chances are the unit itself just corroded up & quit.

I'm wondering, lets say by chance the wires are fine, since your gauge does have some movement, If you can work the drive up & down a dozen times to work it out? Wishfull thinking? What do you guys think?

 

[Slippery When Wet]

I don't have the hands on experience that Quint and these guys do, but after studying the system & tracking down the problem on my own boat, I agree, the design is crap. You will have to pull the boat if you want to do anything other than test the gauge, the actual switches or the wireing back to the transom.

You did not mention that the drive was off the boat or worked on during the off season. That would be a huge factor if it was. In my case, the drive was off, worked on & replaced. I have come to the conclusion that the way the wires come out of the unit & are fed through the housing, they can not take the abuse that my marina mechanics dished out.

The possibility of a wire failure due to damage or a bad ground is always there but chances are the unit itself just corroded up & quit.

I'm wondering, lets say by chance the wires are fine, since your gauge does have some movement, If you can work the drive up & down a dozen times to work it out? Wishfull thinking? What do you guys think?

Yes, the drive was pulled last fall for full winterization by professionals. that could very well be the cause, thanks.

And yeah, I did run the drive full up and down several times hoping it would "work itself out"...no such luck.

 

[Quint4]

Pulling the drive should not affect trim senders as they are attached to gimbal housing. The usual trouble is wire degradation between the sender and the entry point at the transom (outside the boat). Here are a few pics of mine.


View attachment 19869

 

[Slippery When Wet]

Thanks Quint4...so it looks like I would have to pull the drive? Screw that, I will wait til fall when I have it winterized.

 

[Quint4]

You have to pull the drive AND the bell housing to run new wires......not much fun.....so I am back to where I started......I don't need 'em!

 

[duckmnn]

Their junk!I just put new ones on my B3.Everybody said stick with Mercruiser stay away from sierra brand.Well I bought mercruiser's they lasted one week and all ready crapped out.I changeds mine while I did the bellows.They won't get changed for a long time now forgot them.

 

[wilmot]

Are you suppose to remove the whole out drive to winterize?