How to test potentiometer (trim sender)

[92excel]

Is there a way to test the potentiometer (trim sender) other then getting a new one and swapping them? Or how to eliminate it for testing purposes?

The Drive will go up and down

My red light on my volvo trim indicator is coming on way before the drive is all the way up (Its reading 7) and is stopping the drive there.. I have checked all the wiring, fuses and relays.. all seem to be fine. If you manually raise and lower the steering helmet the indicator does adjust the number being displayed depending on its position. so all seems to be fine minus it thinking it is already all the way up.

I have the the square digital indicator and the following pump:

 

[havasuboatman]

Re: How to test potentiometer (trim sender)

Your trim indicator is working correctly. So is the trim limit switch. The red light is telling you that you have reached the TRIM limit. Above that your drive has no laterall support and shouldn't be lifted any higher while the boat is in gear.
To lift it higher (for trailering) use the other button. IE, the trailering button.

 

[92excel]

Re: How to test potentiometer (trim sender)

With the boat sitting level, the drive is not very far (about an inch) off the garage floor when the red light comes on. I was pretty sure you should be able to trim up higher.

I have a button on the dash labeled tilt up which i believe is the trailer button? pushing that to the up position makes a click in the relay but nothing happens. I assumed that was associated with the red light aswell.

 

[havasuboatman]

Re: How to test potentiometer (trim sender)

How far out does the drive move from the full in/down position. Put the drive down all the way, then measure the distance between the mounting bolts on one of the trim cylinders, Then trim it up as far as it will go, and measure it again. What is the difference between the two, and what kind of motor/drive are we talking about?

 

[92excel]

Re: How to test potentiometer (trim sender)

The Engine is the 1992 volvo penta 230 A The Drive is the 1992 Volvo SP

I cant get the drive all the way down as the skeg will hit the garage floor even when i drop the bow down as far as the tongue jack allows.

So on the indicator the farthest down i can go is about 5 then the skeg will hit and the farthest up i can go is 7 then the red light comes on..

The mounting bolt is only an inch or so from the cylinder at the 7 position.
(this measurement is a guess as i am at work)

 

[Don S]

Re: How to test potentiometer (trim sender)

What you need to do is set it, not test it. When all the way down, you should have minus 5 or 6 degrees (depending on transom angle) then the trim will stop going up at plus 7 degrees.
Back the trailer up on a couple of 2X6's so you can put the drive all the way down and see what it's set at.

 

[92excel]

Re: How to test potentiometer (trim sender)

ok so at the lowest point it is at -6 and at the highest point it is about 7.. so i guess it is working the way it is suppose to?

i guess i need to know why the trailer button is not working then. my appologies. i thought trim went higher then 7 degrees.

no matter what position the outdrive is in i cant get the tilt button to do anything other then get make a click in the relay.

 

[Don S]

Re: How to test potentiometer (trim sender)

i guess i need to know why the trailer button is not working then.

It probably doesn't have a trailer button. If you do have another button, once you get to the trim limit, push the over-ride button AND the trim up button. Then it should go up.

 

[92excel]

Re: How to test potentiometer (trim sender)

well consider me as an idiot .. as everything is working as it is. the guy that sold me the boat said you just had to hit the switch and it would put the drive up.. holding it down worked..

what would be the angle at which i would want to trailer?

 

[Don S]

Re: How to test potentiometer (trim sender)

what would be the angle at which i would want to trailer?

All the way up.
Once all the way up, hit the down button to releive the hydraulic pressure on the pump. 1 second down will be plenty.