Shorted trim gauge?

[vroom ZOOM]

Hi there, I have a problem that has me STUMPED. When I push the button to turn the nav lights on, the warning horn comes on and I can hear the high pressure fuel pump on the engine kick in! Say WHAT???? Yes, this is with the key out of the ignition. So I pulled the dash and all the wiring thinking that the engine on power wire got shorted to the blue instrument cluster wire - nope. So next I unplugged the blue wire from each gauge - problem goes away. Just by luck when putting it back together I noticed that the problem occurs when I put the bulb in the trim gauge! On my outboard, the gray wire is the wire that gets energized when the key is on. The gray wire also goes to the dash to power up the instruments. So well I grabbed a test light, unplugged all the wires from the trim gauge except for the blue one, put the bulb in, and turned the nav lights on. Testing between ground and the power terminal on the gauge where the gray wire would connect, the test light turns on! so it seems like it is shorting through the bulb, ground, gauge and into the power supply??? what the heck? Is this normal? With the nav lights on the trim gauge works normally! How do I fix this?

 

[alldodge]

Its an electrical problem but would be better if we knew what motor ?

 

[GA_Boater]

2 questions - Did this issue appear out of nowhere and what was the last thing you did to the boat before it began?

 

[vroom ZOOM]

Issue resolved - it just dawned on me! Grabbed my test light, and yes, there was no ground at the trim gauge! Outboard was a 2008 suzuki DF200. In the factory wiring harness behind the dash there was a plastic sleeve and all the grounds came out of it into the instruments. the ground that went into the trim instrument was TOAST. So I hooked in another one, and voila! it worked! Thank you! The issue did spawn out of nowhere, not sure when because this was the first time I ever pushed the nav light button on this boat, I got it fairly recently and had it out the first time the day before yesterday (3 months of work was needed to get it fixed)