Trim on throttle won't go down, transome switch does

[jkust]

Hi, all on my first ride since last weekend and the trim on my Mercruser shifter won't go down. The up switch will trim up and the transom tilt switch goes up and down. Not sure what to check. Lots of wires in the bildge and connecting to the trim pump, not sure which does what. Only thing I can think of is that I cleaned and rinsed the bildge and it sat for a week and maybe got some water around the trim pump and wires. Lots of plugs and connections, not sure where to go from here. I suppose the trim switch coincidently went out. Anybody have any suggestions? This is a standard Mercruiser shifter from the early 2000's controling my Bravo 1.

 

[Scott Danforth]

It's probably the switch in the handle itself

 

[Texasmark]

Your PTT wiring may be run alongside your regular engine wiring harness if you have the 8 pin connector at the engine. If so it should have at least a blue and green (may include a white stripe in each) wire. I'd look on the engine end adjacent to where the engine control cable connects to the engine harness.......Or it may tee into the wiring at your engine switch. Pull the connectors and with a DMM check for 12v on the green wire (sky blue up, green grass down) when the control switch is held in the down position.

If no voltage present and if you have a Commander 2000 or 3000, it's no big deal to remove the backing plate from the T handle where the switch is located to access it, or you could start there. I'd start at the engine as you have all the wiring in the circuit. If you test at the switch, you may get a good reading but may have an open wire back to the engine.

 

[jkust]

Ok, I did the multimeter trouble shooting this morning. The switch is good it turns out and I tracked the problem to corrosion in the female end of the plug that connects to the wires from the transom switch that then connects to the trim pump. The female end is so corroded and very narrow so have had a hard time getting it to keep working since I can't get in there very good to clean it. I tried some rust remover but that didn't work as well as I thought. At least nothing is broken and I forced me to learn how to trouble shoot this issue. Will see what I can do to clean it out better but for now it is working.