Z21 big motor randomly trims up

[Airbear72]

I have a 2017 Z21. My problem is the big motor will randomly trim up on its own after I turn the power on at the console panel and crank the motor. Note works fine with the ignition switch in the accessory postition or console panel powered off. Also the nav lights turn on randomly.

If I crank the big motor first then power the console panel on it still does the same thing. Here is the fun part, he said sarcastically, it randomly does this during the day. It will happen hours into the day, stop, then happen again. Sometimes it goes days with no issues.

I need the power on the panel to keep the live wells running and operate the nav lights.

In my troubleshooting I have disconnected the bow panel and the blinker switch as that was simple. I have not disconnected the shifter trim switch yet. Why, not? Because, once again all works fine with the power off at the panel.

I am thinking about the trim relays or shorted wires on the trim circuit but If they were bad wouldn't it do the same thing with the console panel powered off? For grins I will swap relays to see if I can get it to to trim down when it happens.

My question are ... what circuit does that console power that could be shorting out the trim circuit? There are no trim buttons on that panel. What else should I focus on?

Thanks in advance.

 

[Andrebass]

Trim switch on motor bad?

 

[olefisherman456]

after replacing relays once and still having problems i carefully examined the mounting/ground. the mount is a poor design . with a small adjustment a solid ground can be done. problem solved.

 

[Joe Winkler]

Console panel has a crack in it and it's getting moisture in the control board inside. I think it's Spider marine electronics that makes them and you can purchase without the middle man. Note: hand tighten the plastic screws as over tightening cracks housing. Not a very well built electronics,

 

[Airbear72]

UPDATE ... swapped trim relays same result. Flustered I decided to focus on troubleshoot wiring harness versus gyessing on a cIrcuit board issue.

Tracing the wires took hours and hours to do. Fingerscrossed here I am hopeful I found the issue. I went 2 hours yestersay with no issues. But we all have had that head fake only to have the problem show up again, am I right? Big test today with a 6 hour trip.

Ok as for the suspected problem. I traced every easily accessible trim wire on my z21. Nothing obvious. Dreading this, I took the shifter panel off. Traced the shifter trim leads. The 3 wires were wrapped in electrical tape and joined a bundle of wires going to the console. I shoved my arm way up in there to feel around, think vet delivering a calf, I felt the bundle of wires resting on top of a screw that held the Ram Phone mount. I removed the mount, powered up and the problem went away. I said " what, no way". What I thought was way WAY worse.

The screw was right in the middle of the bundle. I suspect the screw threads cut through wire insulation over time and continual bouncing on the water and shorted some wires. One of the wires had to be powered up only after the master at the console power was turned on, otherwise the motor would trim all the time. I wish I could confirm this visual but for now the problem is gone.

If, after a successful day fishing with no issue .. I may, just may, take back all the bad things I said about the design team's moms.

One other take away, you would be surprised at the amount of screws hiding in dark places. My hand is all scratched up.

 

[Joe Winkler]

UPDATE ... swapped trim relays same result. Flustered I decided to focus on troubleshoot wiring harness versus gyessing on a cIrcuit board issue.

Tracing the wires took hours and hours to do. Fingerscrossed here I am hopeful I found the issue. I went 2 hours yestersay with no issues. But we all have had that head fake only to have the problem show up again, am I right? Big test today with a 6 hour trip.

Ok as for the suspected problem. I traced every easily accessible trim wire on my z21. Nothing obvious. Dreading this, I took the shifter panel off. Traced the shifter trim leads. The 3 wires were wrapped in electrical tape and joined a bundle of wires going to the console. I shoved my arm way up in there to feel around, think vet delivering a calf, I felt the bundle of wires resting on top of a screw that held the Ram Phone mount. I removed the mount, powered up and the problem went away. I said " what, no way". What I thought was way WAY worse.

The screw was right in the middle of the bundle. I suspect the screw threads cut through wire insulation over time and continual bouncing on the water and shorted some wires. One of the wires had to be powered up only after the master at the console power was turned on, otherwise the motor would trim all the time. I wish I could confirm this visual but for now the problem is gone.

If, after a successful day fishing with no issue .. I may, just may, take back all the bad things I said about the design team's moms.

One other take away, you would be surprised at the amount of screws hiding in dark places. My hand is all scratched up.

Glad ya found the problem, fingers crossed

 

[DONAOL]

UPDATE ... swapped trim relays same result. Flustered I decided to focus on troubleshoot wiring harness versus gyessing on a cIrcuit board issue.

Tracing the wires took hours and hours to do. Fingerscrossed here I am hopeful I found the issue. I went 2 hours yestersay with no issues. But we all have had that head fake only to have the problem show up again, am I right? Big test today with a 6 hour trip.

Ok as for the suspected problem. I traced every easily accessible trim wire on my z21. Nothing obvious. Dreading this, I took the shifter panel off. Traced the shifter trim leads. The 3 wires were wrapped in electrical tape and joined a bundle of wires going to the console. I shoved my arm way up in there to feel around, think vet delivering a calf, I felt the bundle of wires resting on top of a screw that held the Ram Phone mount. I removed the mount, powered up and the problem went away. I said " what, no way". What I thought was way WAY worse.

The screw was right in the middle of the bundle. I suspect the screw threads cut through wire insulation over time and continual bouncing on the water and shorted some wires. One of the wires had to be powered up only after the master at the console power was turned on, otherwise the motor would trim all the time. I wish I could confirm this visual but for now the problem is gone.

If, after a successful day fishing with no issue .. I may, just may, take back all the bad things I said about the design team's moms.

One other take away, you would be surprised at the amount of screws hiding in dark places. My hand is all scratched up.

Just an idea. Get one of those cable cameras and video along the wires to get some piece of mind that the other screws aren’t cutting into the wires also.