Troubleshoot trim switches on a Mercury Commander 4500

davidbrooks

In the never ending game of maintenance whack a mole.  My trim stopped working on my outdrives.   I noticed that one was only going up and then both stopped working completely.  I can jump out the trim motors by putting power to either the blue or green wire and it will raise and lower the drives.  I just recently replaced both brackets and solenoids with https://nuwavemarine.com/mercruiser-stainless-steel-trim-pump-bracket-w-wiring-solenoid-862548a1/
So i don't think it is that. Especially as both of them went pretty close to each other.    However i would like to prove it.  The wiring harness going into the solenoid is 3 wires (Red, Green and Blue.  Green and blue should correspond with up and down and i am thinking Red is just positive.  The question is does anyone know how many volts goes to the solenoid?  I don't want to just jump it with 12v and burn out the solenoids.  The next is the switch assembly.  I tested the rocker switch on the handle and i think that is fine.  It plugs into a harness with the two individual switches that also will put the outdrives into trailer position.  This then goes to a black sealed square.  Anyone know how to test the switches and the function of that square?

Ian

The solenoids are 12V and in fact part of the troubleshooting in the Mercruiser manual is to jumper 12V to the solenoid from the battery. You said you did the motor but did you do the solenoid? Do the 2 switches fro trailering work the pump or not? If so and it’s just the single trim switch then it looks like the black box is the issue (I’m not sure but likely a diode pack that allows you to drive both at once with one switch for trim but using either lift switch won’t feed the other)

davidbrooks

The switches don't work.  As for jumping out the solenoids i was just not sure where to jump them or how much voltage.  I was hoping to jump them at the round 3 pin terminal coming in to the bracket but wanted to ask here also.

davidbrooks

OK Got it.  Found this site  http://marine-engines.wikia.com/wiki/Troubleshooting:_Trim/Tilt_Does_not_Work and it explained it perfectly.  So it looks like my switches are fine.  Put an ohm meter on the switch from Red to purple.  Hit the up switch and it connects.  Red to green and down switch and it connects.  Red to Blue and switch to trailer mode and it connects.  So back to the boat to see if my solenoids got fried.  

Dream_Inn

Solenoids are probably one of the cheapest parts you can buy for your boat.  Hopefully that is all it is.