Trim Indicator

[Daniel P Thomas]

Last season my Starboard Trim Indicator showed full up.
Using the throttle mounted switches did nothing.
Starboard outdrive did raise and lower.
Port worked fine and showed on the gauge.

What is the next logical step to locate the problem?
Thanks
Dan

 

[JimG]

Check/clean the sensor on the gimbal ring at the drive.

 

[Daniel P Thomas]

Thanks Jim

I will look at outdrive this weekend when I am at the boat.
Dan

 

[JimG]

There is one each side of the gimbal... one for trim sender and the other for trim limit. Sorry, I don't remember which is which.

http://216.37.204.206/shorts/mercruiser_OEM/Mercruiser.asp?Type=13&SubType=113&A=44&B=10

 

[Henry Boyd]

You can try cleaning the sensor, but usually when the gauge stays up and the drive goes down, the problem is the sensor itself.

Henry

 

[techmitch]

Trim position sender is on starboard side.

http://www.outdriveshop.com/trim_gauge_pegged.html

Hope this helps.

Mitch

 

[JimG]

Trim position sender is on starboard side.

http://www.outdriveshop.com/trim_gauge_pegged.html

Hope this helps.

Mitch

Good link... thanks! :thumbsup:

 

[jason78]

During a discussion with my mechanic a while back on this topic, he told me there is a round chip or card of some kind within the trim sender housing. He said that usually when the sender goes out, it is because the O-Ring failed and the chip went bad. He said many of the cases he has seen, simply replacing the chip fixed the problem as long as the wires were OK. I will admit I did not ask him and have never seen just the chip for sale apart from the kit. I am not sure if he just takes the chip out of the new sender to try it before installing the whole thing or what.

I have heard it is a very labor intensive process to install a new set of senders so if you can find the chip, you may want to consider trying that first.

I had a case on my last boat similiar but the gauge was moving just a little. He unplugged the main harness on the back of the engine where it all ties in and got a knife to clean the terminals and that fixed the problem. I was convinced the sender was bad and he had it fixed in 5 minutes.

 

[tdschafer]

That happened to me several times over the years with my old 260. It was the sensor every time!!

 

[JimG]

During a discussion with my mechanic a while back on this topic, he told me there is a round chip or card of some kind within the trim sender housing. He said that usually when the sender goes out, it is because the O-Ring failed and the chip went bad. He said many of the cases he has seen, simply replacing the chip fixed the problem as long as the wires were OK. I will admit I did not ask him and have never seen just the chip for sale apart from the kit. I am not sure if he just takes the chip out of the new sender to try it before installing the whole thing or what.

I have heard it is a very labor intensive process to install a new set of senders so if you can find the chip, you may want to consider trying that first.

I had a case on my last boat similiar but the gauge was moving just a little. He unplugged the main harness on the back of the engine where it all ties in and got a knife to clean the terminals and that fixed the problem. I was convinced the sender was bad and he had it fixed in 5 minutes.

I don't think there is any "chip"... from what I remember its more like a potentiometer made of a printed circuit board with breaks in the circuit (switches) at the limits... just varies resistance depending on position.

Yes, water leaks in eventually and compromises the the pot and switch points.

 

[techmitch]

Yep, potentiometer/variable resistance sender unit. Just like your fuel sender unit. Simple two wire sender/sensor.

 

[jason78]

I don't think there is any "chip"... from what I remember its more like a potentiometer made of a printed circuit board with breaks in the circuit (switches) at the limits... just varies resistance depending on position.

Yes, water leaks in eventually and compromises the the pot and switch points.

It is in there. You will see it when you open up the sender. Admittedly, a chip is probably not the best term to describe it. It is a circular white circuit board as I recall but it has been a couple years.

 

[Daniel P Thomas]

That said, if the sender is bad I might as well wait until I pull the drives to replace bellows at the end of this coming season.
Just live with the gauge pegged for the season.
Dan

 

[JohnEGraham]

Buy the "Mercruiser" not the "Serria." Its a big job to run the wires properly. You think they would make it easy since they don't seam to last that long. JG

 

[tdschafer]

That said, if the sender is bad I might as well wait until I pull the drives to replace bellows at the end of this coming season.
Just live with the gauge pegged for the season.
Dan

Dan,
When this happened to me it was usually followed by the Trim Limit switch in the same season. If that happens it will stop your drive from coming up. To circumvent this I usually used the trailer switch and counted up as I started with the drive fully down. Since your other drive is still working you may want to count how long it takes to get to the limit so you will have an idea if the limit switch craps out. Just my 2 cents!!:smt001

 

[Daniel P Thomas]

tdshafer

Thanks for the info.
Thankfully, I do not have to raise my drives unless I try and get in closer to a beach, but even that is rare.

As a matter of fact I almost never even use the trim while out cruising.
I rely on the Bennett Auto Trim Control I installed a few years back.

When I go down to the boat Sat, I will take a look at the sensors and see if anything can be repaired from the outside for now.

Dan