If I understand you correctly, you are saying some lights work correctly and some do not work at all. Did I get that right?
1. Did you check all of the 12 volt DC fuses? They would be near the power converter area.
2. If all the fuses are OK, the battery is good, then you might have a wiring issues. It is common they do a parallel daisy chain from 1 light to the next. Especially if they are sort of all in the same area. What may have happened is the one light had a wire come loose or corrode and then the rest went out as that power wire feeding them went dead. And in this case, Sunline ran both a DC negative and a DC positive wire. Ether could have issues.
Are you handy with 12 volt DC wiring and have an ohm meter or a 12 volt test light? You can back into which wire is the ground and which is the hot. Pull the fixture down, most have screws holding them on. And look for the wire nuts buried up the hole in the paneling they drilled. If there is a white wire, that is DC negative. The black would be DC positive. If they are both black...you need to use back into which is DC negative and then the other is positive. You can jumper in power into that loop and it they all work, then you have to sort out where the connection was broke. And jumper in a DC neg ground wire too.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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