Wow I have been fighting this for several evenings. I am swapping engines and dropping in a 496 Mag HO in a Challenger that has the Smartcraft gauges. My problem is I can't get the gauges to stop showing a trim sensor fault. I have two sets of the common wires that come from the outdrive that look like black speaker wire. I've tried hooking up analog or digital and nothing works. What on earth should those two sets of wires be hooked to to stop showing a fault.

I think those are only the tilt trailer switch wires on a reg. Gimbal ???!!!
What would u do if its a HP gimbal with no wires and the mechanical indicator ??? THATS THE QUESTION !!!!

I would say delete it in the smartcraft system.

How ? ..............don't know , sorry.

Are you going from a standerd transom and gauges to smart craft gauges and engine? if yes then I believe you will need a new smart craft trim sender assy. Merc part # 863187A1.To see what i am talking about go bam marine parts look up with pictures,then merc stern drive ,then select product line,then go to all bravo drives,then transom assy smart craft then open gimbal ring and steering lever, see # 25,26,27. I believe you have # 6 that I do not think works for you. the easy way to tell if you have new or old style is the old one will have four screws holding a cover on. The new one dose not have screws and is a lot thicker. this is just my guess good luck.

I saw that too and I'll look to see what I have but the trim sender and smartcraft gauges have stayed in the same boat. Just the engine has changed so it's gotta be the wiring hookup between transom and engine through the digital hookup

What and where did the old engine go ?.Do you have a blue wire harness from helm to engine pluged in. Dose all you'r gauges work right now.

Yes plugged in digitally and everything works but this one sensor fault. Do I have to reset or reprogram the smartcraft gauge?

Do you have a smart craft gauge manual of any kind to see if you can reset the system and also see if you are missing a plug type wire harness at the transom.this is a hard system to work with out any manuals on hand.

No manuals. I downloaded a manual from Mercury's website.

I bought my Formula with the SmartCraft SC5000 and Stainless Marine mechanical trim indicators. The bracket for the mechanical trim indicators replaced the original trim sending unit. Formula just clipped the wires and installed the bracket. Everytime I started the boat I would get a trim sensor fault. Worked with Formula and Mercury to try everything to get rid of the fault, but the software didn't allow it. Stainless Marine came though by designing a bracket that also allowed the original trim sender to be mounted, but even after that it STILL gave a fault when turning the key on. Ended up that the SmartCraft unit needed to go through a complete rebooting process. Not exactly sure how to do that as it was done at a dealer. I recommend looking into that. Good luck!

Oh, and I do remember it took multiple calls from the mechanic to Mercury tech before finally finding someone that knew what the heck to do. This was in 2006 and it seemed like very few people knew anything about SmartCraft. Hopefully that has changed...

Well there is a master reset on the smartcraft tach but it goes back to factory settings and I lose all my calibrations.