Need trim sender help please
 

So I bought an old Baja 280 with Merc outboards 225 (3.0) carb engines. Unfortunately I can't read the ser # on the tag and haven't located the one on the freeze plug yet. The port side trim gauge works fine but the stbd didn't. PO told me that he installed a new trim sender on it trying to fix it. I found a loose ground wire on the back of the gauge and now the gauge works backwards. Up is down and down is up. I have come to the conclusion that this must be the wrong sender. It would have to be mounted on the STBD side of the engine to work correctly and mine are mounted on the port side. The part # of the non working sender is 8M0071360. The part # of the working sender in 8M0071436. Can anyone verify this? anything I might be overlooking? Any leads on a 8M0071436 sender? A google search pretty much came up with nothing. Thanks in advance, Joe

Joe, good to see you are getting back on the water. Hope all is well and best of luck.
P.S. No more deals on the "Joe Morgan whiskey"

Thanks Gary. I am down to my last couple of bottles, could have used another case.

I'll ask again for you.

Sounds to me like the wires are just reversed if the gauges is working but backwards. These are simple potentiometer's and from what i remember the alphas and bravos use the same ones. Im assuming you have an R/MR/or alphas on your boat. Looking at mercruiserpartsdotcom it shows the original ones are NA but are superseded by these: https://www.mercruiserparts.com/8053...-kt-alph-brv-1
before replacing the sender i would go to the inside of the transom where the wires come through and flip the connections if possible...if not then at the gauge....its probably just wired wrong...then im sure you will also need to adjust the sender to read the actual position properly as well....

Outboards. If you switch the wires, it doesn't change the resistance through the sender, the blade is physically turning the wrong direction. These are 2 wire senders. 1 wire is grounded and the other wire goes to the gauge.

Joe, I'm pretty sure your gauge is installed up side down.
Your Welcome

Senders are on the wrong sides. Port is limit and gauge is starboard

Senders are mounted on port side of both engines. There is no provision to mount them on stbd side

Sorry, OB

I'm finding that numbers listed above are NLA
Looking up 225 (3.0 carb) all S/N list new sender as item 15 p/n 8M0098273
https://www.mercruiserparts.com/bam/...32484/1945/340