Nav Lights - Sidelights stopped working

[hinzee623]

So, I checked the bulb, bulbs are okay. I put a voltmeter on it, NO power. (check it to the mast light, got 12v reading). So something up with the side light circuit. I found the 12|12 connection under the helm. I have no idea where the 12|8 connection is. Looked under the helm. Looked through the nooks in the bridge. Looked behind the 12v panel in the salon. Looked in the kitchen cabinet where the bundle comes from the bridge to the 12v panel. No sign of it.

[hinzee623]

The bulbs are fine. I checked the circuit using a voltmeter, NO power. Check the mast light as gut check, read 12v. So appears something happened to the #8 circuit (from KM1125 circuit diagram). You can see the 12|12 connection under the helm. Can't find the 12|8 connection. Looked in the obviously places, nothing. To be continued......

[hinzee623]

Source of the post Did you check for voltage at the lights? Often its just a bit of corrosion on the bulb contacts.

The bulbs are fine. I checked the circuit using a voltmeter, NO power. Check the mast light as gut check, read 12v. So appears something happened to the #8 circuit (from KM1125 circuit diagram). You can see the 12|12 connection under the helm. Can't find the 12|8 connection. Looked in the obviously places, nothing. To be continued......

[bud37]

Source of the post The bulbs are fine. I checked the circuit using a voltmeter, NO power. Check the mast light as gut check, read 12v. So appears something happened to the #8 circuit (from KM1125 circuit diagram). You can see the 12|12 connection under the helm. Can't find the 12|8 connection. Looked in the obviously places, nothing. To be continued......

I know you checked but how......did you check the wires behind the fixture or just the bulb socket ?

Past that , unless you can find that connector and its ground I don't have any ideas.

[hinzee623]

Source of the post

Source of the post The bulbs are fine. I checked the circuit using a voltmeter, NO power. Check the mast light as gut check, read 12v. So appears something happened to the #8 circuit (from KM1125 circuit diagram). You can see the 12|12 connection under the helm. Can't find the 12|8 connection. Looked in the obviously places, nothing. To be continued......

I know you checked but how......did you check the wires behind the fixture or just the bulb socket ?

Past that , unless you can find that connector and its ground I don't have any ideas.

I checked them at the lug connector, directly in contact with the wire.

[km1125]

I don't know specifically where the #12 connector transitions to the #8 connector (or just where the #8 connector might be). I'd suspect it's either under the bridge helm or in that compartment on the starboard side of the bridge at the footwell of the forward seating... basically right behind your horns. There should be a round access port there. That is where the bridge wiring transitions down into the cabin and there's the bundle of wires there.

Note that the #8 connector has individual grounds for each set of lights. Those ground terminals under the helm (both the bridge and lower station) have the AWEFUL push-on terminals for all the grounds and the power for the helm feeds. You'd be wise the change those out with screw-down terminal blocks, because even if they DO make a connection, you DO get some voltage drop after they've aged a bit. I posted a thread from last year (viewtopic.php?f=13&t=5403) where I took on that project on my 3607 and it was a huge improvement. I did a similar project for the lower helm (there's thread in that Projects forum somewhere too)

So, because they have dedicated grounds, you need to check the ground separately from the 12 side of the bulb to know which side you need to troubleshoot. Take your meter negative lead and attach a LONG wire to it and connect to a KNOWN GOOD ground (like the battery negative terminal or some other KNOWN GOOD negative terminal block). Then you can check for voltage one one side of a connector and for continuity to ground on the other side (or wherever you don't have voltage). Always check for voltage first, then, if you don't have any, check continuity to ground.

Look for those little wire markers wrapped around the wires. The sidelight wires should have an "o" on them.

[hinzee623]

Source of the post I don't know specifically where the #12 connector transitions to the #8 connector (or just where the #8 connector might be). I'd suspect it's either under the bridge helm or in that compartment on the starboard side of the bridge at the footwell of the forward seating... basically right behind your horns. There should be a round access port there. That is where the bridge wiring transitions down into the cabin and there's the bundle of wires there.

Note that the #8 connector has individual grounds for each set of lights. Those ground terminals under the helm (both the bridge and lower station) have the AWEFUL push-on terminals for all the grounds and the power for the helm feeds. You'd be wise the change those out with screw-down terminal blocks, because even if they DO make a connection, you DO get some voltage drop after they've aged a bit. I posted a thread from last year (viewtopic.php?f=13&t=5403) where I took on that project on my 3607 and it was a huge improvement. I did a similar project for the lower helm (there's thread in that Projects forum somewhere too)

So, because they have dedicated grounds, you need to check the ground separately from the 12 side of the bulb to know which side you need to troubleshoot. Take your meter negative lead and attach a LONG wire to it and connect to a KNOWN GOOD ground (like the battery negative terminal or some other KNOWN GOOD negative terminal block). Then you can check for voltage one one side of a connector and for continuity to ground on the other side (or wherever you don't have voltage). Always check for voltage first, then, if you don't have any, check continuity to ground.

Look for those little wire markers wrapped around the wires. The sidelight wires should have an "o" on them.

Agreed on the push on terminals. I've wired a few 12v light switch and usb charger to the helm and my rats nest of wire is all coiled right in front the busses, PIA to work under there. Looking at your old thread it appears my rats nest is twice the size. Its a real mess. Like I mentioned in my original post, might be easier rewire and clean circuit.
I did look through all the nooks in the bridge didn't see any #8 connector (or any connectors once the bundle leaves the helm). I think I might try and snake the path (starting at the light and listening for the path throughout the boat). We'll see....the saga continues. This project is really frustrating because it prevents me from taking it out until its fixed

[km1125]

Here's something you can do to isolate the circuit that might work:

Have power OFF to the nav lights. Even cut off the circuit breaker to nav lights so there's no inadvertant power.

Open one of the side lights and verify you have GOOD continuity from one light terminal through the light and to the other terminal. Note how much resistance goes though the light. Connect one end of your meter on one end (either end, doesn't matter) with a LONG lead - long enough so you can bring the meter up to the bridge helm.

Remove each negative lead on the push-on buss bar at a time and measure if there is continuity to the sidelight that you've connected to. You should be able to find one of those dozen or so connections that has continuity, but only one. Follow THAT lead back to where it comes from and you should find connector #8 and the corresponding positive lead for the sidelights.

[hinzee623]

Source of the post Here's something you can do to isolate the circuit that might work:

Have power OFF to the nav lights. Even cut off the circuit breaker to nav lights so there's no inadvertant power.
Open one of the side lights and verify you have GOOD continuity from one light terminal through the light and to the other terminal. Note how much resistance goes though the light. Connect one end of your meter on one end (either end, doesn't matter) with a LONG lead - long enough so you can bring the meter up to the bridge helm.

Remove each negative lead on the push-on buss bar at a time and measure if there is continuity to the sidelight that you've connected to. You should be able to find one of those dozen or so connections that has continuity, but only one. Follow THAT lead back to where it comes from and you should find connector #8 and the corresponding positive lead for the sidelights.

Problem solved! If looking at your wire diagram: the ground wire coming off of circuit 8. Goes back to the negative bus under the helm. That negative was disconnected off the the bus. The connector was damaged. So replaced the connector and problem solved. Lights are functional! Luckily it was labeled ‘O’ if not it would have just blended in with the rest of the rat nest. Appreciate all the help and suggestions from everyone!

[Midnightsun]

Thanks for posting the solution, much appreciated.