I cleaned my trim limit sender and trim gauge sender yesterday. After completed I went to move my trim up but it wouldn't go. The trim was all the way down but would only go up with the trailer up button. I don't know for sure if this was happening before I cleaned everything because I didn't try. I managed to have the trim up button pinched in the up position with vise grips while I try to spin the trim limit but nothing worked. I also tried jumping the two little metal plates in the limit switch with the trim switch being pushed up but still nothing. Down works fine, trailer up works....So what could the problem be??
Any help is appreciated.

Thanks

Sounds like you took the senders out of the drive, cleaned 'em up, put 'em back in, right?

Well, if so, I'd say the trim postion sensor is not in the same position as when you took it out. Those things are pretty touchy, you have to install them just right. You may have installed it off a few degrees rotationally. This may be causing it "sense" full up, thereby not allowing you to trim it up.

I did take out both senders but I was very careful when I put them back in. Not 100% certain if the trim was even working before I cleaned the senders because I never checked.

How can I test the senders?

check for power at the switch . Had a similar issue and it was a bad switch after all the hunting.

we had a alpha that had that problem a couple times. i think our issues were with a broken wire on one of the trim pucks (i think they are called that).

I had a similar problem- could trim down but not up-could only use the trailer up to bring the Bravo up. I found 2 problem areas. I removed the round position sensors on the drive and cleaned the contacts on each one and I also found a bad wire at the plug that connects to the trim pump(3-wires in one plug). Somehow the one wire was not passing power through the plug, I checked it with a test light and found out the wire was actually broken/corroded inside the plug. I had to cut the plug off and put the 3 wires individually directly connected to the male plug coming from the pump. the boat had sat for 5 years so it had some issues with corrosion. but after all of this it worked fine. Hope it helps.

Try jumping the two wires on the trim pump selinoid,and see if it works after that.

I just encountered exactly the same issue on my 382 rebuild. Since I don't have Mercury drives, I cut the trim sensor wires out of the harness. What I failed to notice was that Formula had spliced the two ends together in order to make all the switches work correctly. When I was done, I had the same symptoms you do. The problem is that the trim sensor switch circuit is (was) open instead of closed.

All fixed. I unplugged the two plugs for the sender b the pump and trim up worked. Went back down to the limit sender and clean it real well with a little sand paper and a pencil eraser and she was good to go. adjusted it to just under 22inches.

Now for the next project of upgrading the sound!

Thanks