I'm assuming you are referring to the flood lights over the bed and in the back of the camper?
While the bulb can have it's issue, I can tell you, the switch on the fixture stinks. The switch is so cheap, it does not make contact, it so hit or miss. Have you checked the socket is getting power?
I just finished restoring a 2007 T289SR and all 4 switches were bad. My friend reported the same thing you are, they never turn on right so we changed them out and now his lights work.
This is a fixture issue in his case. The switch was super cheap all plastic and just plain was a bad setup. It seems the 2006/2007's may be more prone to the switch issues. I know the 2004's have had switch issues too, just not as bad at the last 2007 I helped with on. The fixture supplier may have changed.
I replaced the switches with these Gardner Bender off of Amazon. Seems the price has stayed the same since March when I bought mine. The pricing for this switch is all over the map.
Hope this helps
PS. if you go to LED, check the wiring polarity on the fixture. It might have to be changed to make the LED work. The incandescent did not care what polarity they are. They have been hooked wrong at times, but it did not matter on the old bulbs.
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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