OMC 2.5L Selectrim Problems

[Litetwin4]

The tilt works great on my boat however the selectrim works intermittently. I first confirmed control power was correctly reaching each solenoid. I then thoroughly cleaned and tightened all the control and power/ jumper leads on the solenoids however no improvement was made. I suspected the solenoids were bad so I jumped power across the leads with no improvement. Any ideas on what my problem is?

 

[Howard Sterndrive]

Re: OMC 2.5L Selectrim Problems

could be the motor.... that "in the bilge" location makes it likely that the motor will be under water at some point. DC motor brushes and commutator bars like to carbon up and are just generally unlikely to live more than a decade in any environment.
If a light rap with a wrench on the motor starts it working, that pretty much confirms the carbon/brush/commutator issues.

 

[Litetwin4]

Re: OMC 2.5L Selectrim Problems

I replaced the original trim motor with a brand new Arco trim motor. That was the first step performed before I started my trouble shooting of the solenoids.

 

[Howard Sterndrive]

Re: OMC 2.5L Selectrim Problems

you say you are jumping power directly to the motor and no go? if so, motor is dead. period.
Maybe try that again with good heavy jumper wire. Run the bilge blower while arcing and sparking with jumpers.
Pretty hard to blame a relay or switch when you have eliminated all that with jumper wires.
Is the motor trying to turn? seized parts don't generally work intermittently.
You say intermittent so I assume all things like seized worm gear/ no grease in it are off the table. Intermittent says electrical connection.

 

[Litetwin4]

Re: OMC 2.5L Selectrim Problems

When it works, the unit runs perfectly without any problem. (about 50% of the time) Agreed, this means the worm gear and the new motor are fine. The solenoids on my boat have three poles. Two large one in which heavy power leads are attached and one which is for the smaller gage control wire. While surfing ebay I noticed some identical solenoids listed as being "grounded". I am under the impression my solenoids are grounded to the plate they are mounted on. Could my issues be due to poor grounding to the plate? If it was due to poor grounding I would not expect the problem to be intermittent.