Motor Trim Running Intermittently

[Fishtales]

Hi,
I noticed on two occasions now that when my engines (Yamaha F250s 1996) were up in the locked position the starboard trim motor would run.

I tried the button on the side of the engine, and it would stop when depressed (either way) but once released it would still run. Same thing when I used the single switch for both motors on the throttle stick. When I press the trim switch for the engine in question (top section of controls) it then stops and everything works normally.

It happens very infrequently so it has been tough to diagnose. Maybe a wiring or logic issue?

Any thoughts appreciated.

 

[BobP]

There's not much to the circuit, a trim relay assembly, some diodes, lots of connectors, plenty of wiring. There is a schematic wiring diagram in the service manual, if you are a DIYer it's straightforward. I'm looking at the HPDI manual, should be similar for the Fs.

You want to open and check all the connectors involved first, since letting go of the switch in both locations still allows the motor to run meaning the resistance is not great enough to drop out a relay, then again the relay may be sticking. Water may have entered one of the swiches or connectors. Find the trim relay module and see if it looks good - no water penetration / salt deposits. Each switch resistance would have to be checked in on and off positions, and the diode assembly to be checked, I think there are procedures in the manual to test each component.

An experienced yamaha mechanic is good, I bet this has occurred before, he will know where to look first, and save time, if he is good, that's the key.

 

[BobP]

You may want to throw Andy a shout at THT, he may give you some clues where to look first if he's seen it before.

 

[JUST-IN-TIME]

nope you got a bad switch on motor or console

i have seen more than 1