Nav Light Problem

gordonvp

I recently bought a used 2008 GS 202 and I'm currently checking basic electrical lighting operations.  Excuse my terminology but my focus has been on the stern light atop the Bimini (ANCH light) because the original plastic spacer, under the bracket that screws to the Bimini bar, was broken and the light was wobbly.  I put some rubber washers under the bracket and it's now very solid.  

The courtesy lights work, as well as the front docking lights.  No problem there.  When I put the NAV/ANCH in the upper position the switch lights both the upper and lower indicator LEDs and the bow lights (red/green Nav lights) light up but the stern anchor light on the Bimini does not work.

During the course of troubleshooting I found that there was 10 VDC (and change, but not 11 or 12 VDC) at the outlet behind the helm seat.  I had taken the plug apart recently because the rubber boot covering the pins needed some repair and I think I reversed the + and - wires.  The black wire should be on the larger of the two pins, so I swapped them, but still no light.  I disconnected the ANCH light plug under the Bimini canvas and checked that the 10 VDC made it from the helm seat outlet to the Bimini plug.  It did.  I checked the bulb continuity and my VOM beeped as it should.  I also checked the continuity of the wires in the light pole to the bulb socket.  Again all good.

After all these checks the ANCH/stern light on top of the Bimini still does not work.  Did I miss anything?  Shouldn't be this complicated.

rdcastle

Reversing the wires shouldn't matter on DC current. It sounds like a switch issue to me. Check your voltage at the red/green sidelights and see what you get. Some of the 3 position switches have a diode built in to block current from one pole or another and this is the way most of the NAV/ANCH switches function.

gordonvp

Thanks, Rob.  I'll try to check the front lights and the switch when I get time.  I don't really use the boat for nighttime maneuvers so the fact that the stern light isn't working may not be a huge issue at this point.  Just trying to make sure things work as they should.

cjjjdeck

If the bulb in the stern light is an incandescent bulb, the bulb should still light at 10 volts applied to it, just a bit dimmer than 12 volts hitting it.

Sounds to me like potentially there may be a couple of issues.  If you haven't done this already, see what your battery is putting out compared to the voltage you're measuring it the light socket.  If the battery is OK at 12.6 volts and you're showing 10 volts, then you may have a ground problem with the nav light circuit.

You may also have a intermittent connection on with the bulb filament so put a spare, new bulb in the socket just to make sure (I always keep spare bulbs for everything on board).