Is there anyway to disable this? I have been driving boats for 20 years and know when to stop trimming my motor. I don't want the boat telling me how much I'm allowed to tim up. I have the single trim cylinder too so it's just in the wiring that stops it.
My gauge was reading off when trimmed all the way down so I tried moving the sender around a little bit to see if that would fix the gauge and allow me to trim it up more while on plane. Now it trims less and I lost 5 mph and 350 rpm.
The boat always ran best at max up trim and if I even slightly trimmed down it lost major speed and handling. I would love to trim up a little more to try and get the bow up more, because I feel it dragging the front, and way worse now after it doesn't trim up as far anymore.
Or does anyone have the wiring diagram for this so i can figure it out?
Normally the sender is adjusted so that when the motor is trimmed fully down the gauge indicates fully down. If the sender is adjusted properly then when the gauge indicates the motor is at the top of the trim range the motor will be at the top of the trim range. Which according to the Mercury Owner's manual is 20 degrees Up from being fully down.
I see that your model motor is limited so that it will not go into the tilt mode (beyond 20 degrees Up) when the motor is running much beyond a fast idle speed. I am guessing that the limit is set by the motor recognizing the sender position but this is just a guess on my part. If my guess is correct then you can "fool" the motor into thinking it is fully down when it actually is not. Trim the motor a few degrees up from its lowest setting and then adjust the sender to the full down position. Then try the motor and see what happens.
Or you can install a wedge between the transom and the motor so that the motor is at a different (greater) angle to the boat than it would otherwise be. The trim gauge will then correlate correctly with the motor but the motor will have a greater Up trim capability with respect to the boat.
I just went to the parts book. Your model uses a trim limit module. I don't have a Mercury Service Manual and therefore can't determine if the module is adjustable or not. I suspect that Mercury does not want it messed with. I also suspect that the trim gauge gets its information from the limit module but maybe not.
Thank you everyone for your input. I really want to completely disable this. I got it back to within 1mph of what it was. I just really want to figure out how to get rid of this. A wiring diagram or a wire that controls this would be great. Again I don't care about warranty.
Please see the Forum Announcements, and be sure to provide the REQUIRED info when posting. Thanks!
A couple of very important pointers:
-This engine uses a DIGITAL trim sender. It's adjustment should not be altered, as it can cause malfunctions and substantial loss of performance.
-TRIM angle (maximum) is PCM Controlled. This is hard-coded programming, and if you attempt to accelerate beyond approximately 2500 RPM's (or trim beyond the max position), Engine Guardian will occur. This is a SAFETY measure. Have an Authorized Mercury Dealer verify that you are achieving the maximum 20 degrees of trim angle.
-A "Trim Limit" kit is also available to install. This is actually a TILT limit kit (designed to stop the engine trim at a fixed position, so as to prevent contact with other objects that might damage the engine).
-Transom Wedges are not acceptable for use (per Mercury Service Bulletins).
Pardon my ignorance, but if the OP has the Mercmonitor, could this simply be a trim calibration issue? I know the manuals walk the owners through it, but I am not sure if that would affect actual trim or just indicated trim?
Since this is a 0-5volt sensor is down 0 volts and up 5 volts? If so you should be able to install a resistor in series with the 0-5 signal wire and make the computer see less voltage which would let you trim it further. Should be able to measure the voltage at full trim then play with a handful of resistors and easily get more trim out of it. I'm having the same issue with mine and can test it tonight
I was out in my shop testing voltages. 0 volts is all the way down and it looks to me to be about 1.5volts D.C. is when the trim shuts down. I'm not telling anyone to do this but it sure looks like a resistor can be added in series with the white wire to make it trim higher than it does now. The 3-wire triangular plug on the left side of the motor red +5vdc, black 0vdc, white wire is the variable 0-5vdc. I've got plugs exactly like that in my shop so would be simple to make up one that would fit right in there and also be able to be removed easily.
Last edited by Northwoodswalleye; 04-23-2017 at 09:12 PM.
Yes but in my opinion the trim gauge already reads incorrectly!! Yes the pcm will see a lower voltage only for the trim sensor but all it is doing with that voltage is limiting trim. The 5 volt power for the pcm will be unaffected. I have the male female plugs in my hand if it ever warms up (snow this morning!) I will test and post
If the pcm sees 1.4 volts instead of 1.5 volts it won't change how the engine runs or create a fault. I understand the engine guardian (cut power if you try to run the motor above the normal trim limits) and it will fault if there is an open circuit in the wiring. Changing the voltage that the pcm sees will only make it seem like the motor is trimmed less than it is. I did order from you last week. Thanks very much