1981 Wellcraft Sunhatch - Odd Control Panel Issue

[emmurphy50]

I have an unusual situation where when I turn on the "panel" switch which should turn on the panel lights, or the two way anchor/navigation switch to navigation (which should have no effect on the panel lights) and a number of the gauges go haywire, including the fuel gauge goes off scale negative, the oil pressure gauge spikes, the trim gauge shows 1/2 tilt (should not read, the sender is bad).

We had a heavy thunderstorm pop up and although under the windshield, things may have gotten a little wet while we got the cover on (also in the engine compartment which was open). I also was poking around for just a few seconds from underneath trying to diagnose some slop in the steering cable, and moved a few wires.

I am an engineer and recognize this is hard to diagnose from a description - thought if someone saw the symptoms, might have a good place to start.

 

[GA_Boater]

Measure the 12 volt feed to the dash, when the gauges are correct andd with the panel light switch on. See if the voltage is dropping, there may a poor connection from the motor or battery going forward.

 

[emmurphy50]

Thanks. Why would that cause the apparent cross feed between circuits at the switch bank and beyond? Oh, the navigation light switch IIRC also turned on the lights for the panel (gauge) lights as part of the short.

 

[emmurphy50]

When I pull a grey-green stripe wire off of the switch, the problem seems to go away, wired to the navigation side of the toggle switch. Why would a feed to the bow light cause the gauges go haywire, and why would the "gauges" switch to light the gauges do also?

 

[MH Hawker]

its a matter of connection points and grounds, when one or two are minimal you just never know what effect will show up

 

[emmurphy50]

Where would the ground block typically be for the panel and accessories in a cuddy cabin boat - early 80s?

 

[GA_Boater]

No telling where it is. It could be under the dash along with a 12 volt buss.

You will have to follow wires from the battery forward. Not always an easy chore.

It may be a good idea to look around where you were poking. A wire could be pulled out of a connector or crimp.

 

[emmurphy50]

I think I fixed it. I noticed it at night with a fresh set of eyes that the dash lights on when it was backfeeding were different then those when the dash lights were on. A nut fell off a gauge and the wires on it were lose, breaking the ground continuity across the dash panel. I need to find a nut.

 

[emmurphy50]

I think I fixed it. I noticed it at night with a fresh set of eyes that the dash lights on when it was backfeeding were different then those when the dash lights were on. A nut fell off a gauge and the wires on it were lose, breaking the ground continuity across the dash panel. I need to find a nut.