Diagnosing trim gauge issues

[Merccoper]

My trim gauge stopped working late last year. The weather has finally turned better and it time to fix it.
I’ve tested the gauge using directions found here in the forums and it appears ok.

Trim up/down and trailer up/down have no impact on the gauge. With the key off or on the needle remains maxed out in the up position.

I removed the the sender caps and they look ok.
Im not sure of what steps to take to diagnose the issue.

Alpha 1 Gen 2

Any help would be appreciated.
Thanks.

 

[04fxdwgi25]

Trim indicator in full up all the time indicates an open circuit (bad sender or broken/disconnected wire somewhere) or a bad gauge.

On back of gauge, with power applied, short the "S" terminal to ground. If it goes full down, the gauge is good and your problem is in the wiring or sender on right side of gimbal.

If you have worked on the back of engine, the wire may have gotten disconnected at the banana plugs.

 

[dubs283]

The sender for the trim guage is most likely the culprit in your case. It's often the number one cause in most trim indication issues. By verifying the guage is operational you now have sender wiring and the sender itself as focus

You can test sender output with an ohm meter connected to the wire ends at the engine harness. Should read approx 30-240 ohms depending on potentiometer location (rotating the hub). Just because something looks okay doesn't mean it is

 

[tank1949]

You should have a trim limit switch and trim sender. The are hard to adjust without a buddy at the helm to provide feedback. However, before installing both, test with a multimeter as dubs 283 implies. The testing will prove whether they are defective or wiring or helm gauges are defective. Been there!!!!

 

[Stinnett21]

Common failure point is the wires as they leave the sender. Turn your wheel hard over as in making a left hand turn to inspect the wires. I've been buying time with mine using liquid electrical tape.

 

[Scott Danforth]

Trouble shooting steps in the factory service manual for your drive

 

[Merccoper]

Thanks for everyone’s input!
Winner was…….the sending wire got disconnected in the engine compartment, likely when I was replacing the steering cable last year!

Your help is much appreciated!!

On to seal kit replacement of the upper gear case. Damn, will the ever end!!!

 

[dubs283]

On to seal kit replacement of the upper gear case.

FYI, alpha one gen 2 requires a rolling torque wrench to set bearing preload upon yoke seal replacement

 

[lcochrane]

Ok so I am hoping someone can help with this issue I replaced the sending units the season before last and the gauge seemed to work fine last year. When I got everything running this year it stopped working, the gauge is all over the place, no matter how much I moved the trim up and down. I did a test on the gauge and according to the test I performed there is nothing wrong with the gauge.

 

[04fxdwgi25]

Ok so I am hoping someone can help with this issue I replaced the sending units the season before last and the gauge seemed to work fine last year. When I got everything running this year it stopped working, the gauge is all over the place, no matter how much I moved the trim up and down. I did a test on the gauge and according to the test I performed there is nothing wrong with the gauge.

Probably should start your own post so you can follow up and not confuse the issues for others.

But

If it bounces all over the place, the contacts in side the puck could be gummed up. Have taken the covers off, pulled the center part out and cleaned the contact surfaces and reassembled. Will fix some, others, not so much.