Mercruiser IO won't go down

[kenorr61]

I have a 4.3 Mercruiser and the lower unit now suddenly won't go down. I hear it click by the motor but nothing moves. I have heard it maybe a relay switch or the solenoid. Can anyone help with diagnoising the problem.

Thank you

 

[JWebber]

Re: Mercruiser IO won't go down

I would start by checking for loose connections first. There is a process for testing the circiuts with a voltmeter and using a ohm setting in a service manual. Somebody here can give you a link for download of that section.

 

[Doernuth]

Re: Mercruiser IO won't go down

Cross the big terminals on the down soleniod with a screwdriver. If the drive goes down it is the solenoid.

 

[bds85466]

Re: Mercruiser IO won't go down

Is the low limit switch somehow falsely triggered/stuck on?

 

[Dryon]

Re: Mercruiser IO won't go down

Cross the big terminals on the down soleniod with a screwdriver.

This might be okay on an auto solenoid, but I would never suggest doing this on a boat. Sparks & gas fumes don't mix well. There's only one way I would test the tilt-trim system and that is to check for 12v power & continuity per the shop manual instructions. Here is a quick check sheet I created. Wire colors may be different, but the general operation should be similar

 

[kenorr61]

Re: Mercruiser IO won't go down

Thank you for attaching the document. I will check it out this weekend.