ddavis

I have searched on the forum, but couldn't find the exact same symptoms as this boat.

Mercruiser Zero Effort controls
Twin 502 mags
Bravo 1 drives


When I use the trim switch on the Zero Effort controls, the starboard drive will not go down. If I use the trailer switch and trim both drives down, the trim switch on the throttle will move the port drive up and down, but the starboard drive won't move either direction. The trailer switches on the dash work as expected with both drives going up and down. The single trailer switch on the stern will operate both drives up and down as expected.

Is it an issue with the switch on the throttle, or maybe a trim limiter switch?

picklenjim

Wouldn't be the limit switch. First place I would suspect and test is the switch on the throttle.

ddavis

After doing a little more research, it looks like it may be the diodes from the switch on the throttle.

ddavis

The switch is working in both directions on the port side drive, but not the starboard.

There are only 3 wires coming out of the switch, so it doesn't appear to be the culprit.

Waverunnering

I found with my formula I had two separate problems when I had a similar problem. I ended up pulling the trim sensors apart and found some corrosion inside of them. Cleaning the contacts adding some dielectric grease and new o-rings fixed the problem. If your limit switch isn't reading it will think that your drive is above the trailer position.

Hopefully the other problem I had is not the case. I had a trim gauge that was not working and discovered that the bell housing bolt that drives the senders was stripped out and not moving at all when the drive was raised and lowered.

Either way my trim button had no control over the Port drive but the trailer button seemed to be fine

ddavis

Thanks for the info. I will definitely look into the trim sensors.