Crazy trim issue!
 

I have a crazy trim / drive problem. 03 Formula 292 Fastech. Key off trailer switches work fine drives up and down. Key on the port drive switch works u/d the STRB you have to keep tapping the switch to make it go up but down is ok.
I swapped the switch, same problem on STRB side. Put a new solenoid, same issue. Bypassed the harness by taking a wire from the up terminal to the solenoid and same issue. Now I’m stumped!

Trim limit switch on port side of starboard gimbal ring

is there a different trim level switch for the trailer mode or the rams limit the trailer trim?

No, when trailer switches are used it bypasses the limit switches.
In the pic below, note the Purple/White wire coming from the throttle handle. This is the trailer feed wire which takes power from the Red/Purple and sends it direct the the Purple/white

The trim limit can be bypassed by connecting the purple White with the Blue/White. If this is done then the drive can be trimmed full up same as trailer switch.


https://cimg0.ibsrv.net/gimg/www.off...1e5d08f9dd.jpg

Thanks for the info! I’m going to jump those two wires to make sure it’s the sender.

Oh I misspoke about wire colors only, not that jumping would bypass.

The Purple/White comes from the trim switch and the Blue/White comes from trailer, otherwise the same

Okay. Turns out it’s not the trim sender. I called Formula and they sent this diagram.

Okay. Turns out it’s not the trim sender. I called Formula and they sent this diagram showing an outdrive control box. It’s wired between the switches and the trim pump. Has anyone ever seen this box?
I’m unable to post diagram.

Now that you have 10 post you should be able to post pic

https://cimg5.ibsrv.net/gimg/www.off...8de96927b.jpeg

OK you have 2 extra relays and 4 diodes, need to find them
I'm unable to find the box

swapped out the relays already.

If those were the small square ones, ok
Need a voltmeter and another person. Measure voltage on the end of the diodes that attach to the Blue wires. Measure one at a time, one goes to port and other to starboard. Need to find out if the diode is passing voltage

We did that and no voltage drop.

OK push up and getting 12V on each side of the both diodes

The trim limit will work the same on this system as with separated one. When the up is pressed there should be power on the Blue/Green and Red/Purple (Separated system would be Blue/White and Purple/White shown above).

If power is on one side but not the other then were back to the trim limit on the gimbal ring

.
https://cimg7.ibsrv.net/gimg/www.off...cc15edd570.jpg
https://cimg9.ibsrv.net/gimg/www.off...5fe9759fe5.jpg

Add a note: I'm guessing what is going on inside the Mercury box
If a part number could be found or maybe a Merc Super Tech could explain or offer some insight.

I'm assuming that the trim limit is keeping the drive from coming up. The system does not appear to have anything which would measure how high the drive is unless its using the trim gauge wiring, but that wiring is not shown on the drawing.

The box is in the gunnel near the helm seat. You really have to stick your head in there to see it.

https://cimg1.ibsrv.net/gimg/www.off...fc46accfd.jpeg
Here is the black trim limit box. Formula had one left so went ahead and ordered it since the port side started doing the same thing. Hoping it won’t be to hard to install.

Hope it works
Don't know if its worth to reverse engineer, but I would think about maybe remove and replace with old school

After thinking about I have to agree. I’m shipping this thing back on Monday and get pump harness.
Does anyone know the part number for the trim pump harness?

This looks like it, appears to be 20 foot
https://www.greatlakesskipper.com/me...kaAhcwEALw_wcB


This is same at BAM
https://www.mercruiserparts.com/46838a6-extension-kit