Motor trims up on its own

Brand new 2008 Ranger 198VX with Yamaha vz200 HDPI.
First time out breaking in motor. Sitting at the dock idling and the motor trimmed up out of the water on its own. Worked all 4 switches (bow, motor, steering, gearshift) several times thinking a switch was stuck. All switches will trim up and down. However, when I turn the key on the motor trims up on its own. The problem stopped for a while so I left the dock, running on plane and the motor trimmed up again on its own. Same problem – switches work – but turn the ignition on and the motor trims up on its own. I made it back to the dock and on the trailer by holding the trim lever down to keep the motor from coming up. I took it to the dealer but couldn’t duplicate the problem. The trim gauge wasn’t working so the dealer adjusted it so it would work. They figured that may have had something to do with it. They have never heard of this kind of problem and said they don’t know what to do about it. I went back to the lake and after about ½ hour the motor trimmed up again on its own while running. Same problem – all switches trim the motor up and down but when the key is turned on the motor trims up on its own. It appears to be a short or some problem that comes and goes with the boat bouncing on the water or on the trailer.
I’m taking the boat back to the dealer next week.

Any ideas? Has anyone else experienced this problem?

Sounds like a short to me... That can be dangerous if your running wot and trims up and out. No steering.. http://www.bassboatcentral.com/smileys/eek.gif Better get it fixed soon.

Sounds to me that the trim system is wired wrong because it does it when the key is turned on? I would say that one of the switches is shorted but because it does it with the key switch on????? You might disconnect each connection until you find the problem, but if left unfixed it will burn your trim motor up!!!!!!!!!

unplug one switch at the time and you will find it ,after about 600 bucks i found the one that burned up my trim motor ,i would unplug the one on the motor cowl first , that was my prob

I'm hoping it's just a switch and not a hard to trace wiring problem. The weird thing is the problem comes and goes, and only happens with the ignition turned on. With the ignition off everything works properly. The ignition shouldn't effect the trim or switches, but when you turn the ignition on it immediately trims up and you have to turn the ignition off to trim down. I sure hope it decides to act up when they start working on it, otherwise they can't trace the problem.

Thanks for all the information. I really appreciate it

Before you check wiring and such, check to make sure the trolling motor cable from the pedal to the head is not "bumping" the trim switch up front. On mine when I would run and hit boat wakes, the cable would bounce on the deck accidentally hitting the switch causing the boat to trim. Hope this is it!

how many trim switches do you have ? one on the control , one on the motor ,one on the front panel and probably one on the steering wheel ? correct ? there could be sometthing wired wrong on the switch that is feeding current to one of the switches with the key on ,maybe two wires on switch shorting from being loose and moving enough to get together . you could slip the bow panel off and unplug one wire on switch ,check to se if it does it then unplug one in motor cowl,check
repeat process till you have eliminated switches . i had all kinds of problems with mine . a spring had broke in relay and it would arc sometime and do it but i think that it all started at the switch on cowl . all else fails process of elimination will find it .good luck and let us know what you find may help someone else .

is there are any switches that wont work unless the key is on? if so that is the switch I'd check first.

on my boat the one on the front panel wont work unless the key is on. all other switches will work anytime. if that were happening on my boat the front panel switch and wiring would be the first one I would unhook.

The dealer found the problem. Said a screw had gone into the wiring harness. They now need to replace the entire wiring harness from the motor to the ignition switch. I'm still waiting for my boat...
Thanks again for all the information and help.