"Wiring problem" solved, but why won't trim gauge work?

[Ron V]

My lack of dash lights turned out to be embarassingly simple. The tach harness seemed to be plugged in all the way but needed an extra "oomph" to get it all the way together. So there was no ground for everything. At least I wasn't going nuts like I thought I was.

But, does a Merc have to be running for the trim gauge to work? The OMC never had to be, it would work just with the ignition turned on. Everything is hooked up by the book and the brown/white wire is plugged in at the engine end. Haven't run the motor yet (going to do that at a dealer to sign off on the inspection for the warranty) so I don't know if this is the trouble or not. Anyone know for sure? It's a Faria electric trim gauge - hardly worth hooking up anyway but hey, it was already in the dash....

[Tom D.]

If it is hooked up correctly you should be able to unhook the bullet connector under the cowl and ground it out to make sure gauge is working properly. If you are able tomake the needle move to the other side of the gauge then the sending unit is probibly bad. To test the sending unit you need a multi meter with OHM's meter on it. One lead to ground other to one side of sender. One side of sender must go to ground. Hope this helps!

Tom

[hydro-cat]

Merc and OMC trim guages work oppisite of each other. The only thing that is needed to make a trim guage work (no matter who's it is), is power 12vdc and a ground and the correct signal from the sending unit. The trim sending unit is simply a varible resistor. If you have not changed guages from OMC to MERC, it is working just the oppisite of what is it was working at before. People are correct, in saying that you should get some kind of needle movment by grounding the brown with white stripe wire. This will tell you that wiring up to the gauge is working, whether or not it is merc, omc or yamaha. Just some kind of guage deflection is what you are looking for. Then just change the guage to MERC style, and everything should work. There will be some adjustment, on the sending unit. And guarranted, it will not be perfect.

Just my opinion.


Tim

[tux974]

What size merc engine are you talking about.

[Ron V]

Motor is a 2005 150 XR6. Thanks for the replies. My honest opinion is that the gauge is a worthless distraction anyway, better off driving by feel and by the tach because the trim gauge is halfway across the dash from the driver's seat and the electric ones drift anyway. But I figured I'd hook it up so that passengers wouldn't have TWO dead gauges to ask about (they already can't understand how the motor runs when the gas gauge reads empty all the time).

[Ron V]

Got everything finished this afternoon, remote trim is all hooked up and everything is ready to go. I did do the ground test and the trim gauge went from all the way up to all the way down, so it is working, just opposite. I plugged it back in, trimmed the motor up and sure enough the gauge came down, but only a little bit in the trim range and then moved down more as I got into the tilt range. So the calibration is off. I looked and don't see how to adjust the sending unit. Electric gauges are crappy anyway, but maybe someone knows how to adjust the sending unit?

[mercmatt22]

the trim sender offers little adjustment if any. replace the guage w/one made for a merc and you should be ok.