www.iFourWinns.com

First time I needed to use my navigation lights occurred recently on my 2005 Vista 348. While running, I engaged the lights, and as quickly as I did so, all my port side gauge cluster (oil, temp, gas, + tach, drive angle, etc.) pegged in the down position and no backlighting came on for these gauges as well. I disengaged the nav lights as I had a short distance to travel safely.

Back in port, with engine off, I engaged the switch again, and this time the gauges all pegged upward. All lights work. The anchor light works on its own while running or with engines off with no impact on the gauges.

Sound like something simple or do I have major issues ahead? All other switches work without causing any such issues. Could the lack of backlighting be connected to this - I am not sure if this model has one light for these all these gauges or if each has there own light).

Any suggestions would be appreciated, and I will not attempt anything too technical on my own - but you ideas may help with my understanding.

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Ernie Follis
It'll Do II
Four Winns 348 (2005)

It does not sound major.

Each gauge has it's own light bulb, but they are all wired together and come on with the bow navigation light. (anchor light alone will not turn on the gauge backlights).

It sounds like you have a bad ground wire somewhere in the gauges, and when you turn on the back lights, the ground wire is being pushed up to 12V instead of 0V. That would effectively de-power the gauges and they would go to peg to zero.

I can only guess that when you tried again, the ground wire went to some other voltage (lets say maybe 4V) having a loose ground connection. That may have been enough ground to activate the back lights, yet give the gauges incorrect readings.

The ground wires going to gauges are usually "daisy-chained" meaning one, to the next, to the next, etc. So one bad connection could effect several gauges.

You can probably find a wire back there that is physically loose. If not, you will need to check with a volt meter. All grounds on the gauges should check 0V to the ground at the fuse block...even with the lights on. (or no more than about 0.2V)

_________________

"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

I don't think the ground wire would be "push up to 12v" A fuse or breaker should have tripped. I think you have a as mentioned. a bad ground wire and its now trying to get a gound though something else. As in your helm/dash lights.

A fuse would only trip due to excess current, not voltage. With a disconnected ground connection, there would be no current, and the ground wire would go up to the supply voltage (until grounded again).

_________________

"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

Yes, in that case very true. But I think what you are saying and what I am trying to say since the ground is off. The gauges are being back feed though the the Nav lights.

@paul: Yes, exactly

@efollis: I hope you do try to fix it yourself instead before paying somebody else. You are just looking for a loose ground wire.

_________________

"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

Thanks for the help folks. It appears you are exactly right. There was a poor connection in a plug that leads to the gauges. After tightening things up, the backlighting and gauges work correctly and there is no more "pinning" of the gauges when the navigation lights are engages. We are now safe to travel at night and can see the gauges clearly at the same time. Merci....

_________________

Ernie Follis
It'll Do II
Four Winns 348 (2005)

Where was or is your plug you fixed? I assume behind the instrument panel? i have a similar problem--white nav light out, drive trim gauges acting funky.
Mines a 2001 Vista 328 (kept in salt water--electricity's worst nightmare)