Today may be your lucky day... We just happen to have a wiring diagram for a T2499... Our one and only wiring diagram... It is from my 2004 unit however yours should be real close.
Sunline Coach Owner's Club - Sunline Owner's Files - Sunline Solaris T-2499 Wiring Diagram
Reading the DC wiring diagram on page 2, the lights are split up on 3 different circuits.
Try this and see if "any" work. This adds to where Gene is having you check.
Circuit 3 = try the cieling light in the bed room
Circuit 4 = try the light over the sink. Also the fridge light was on this and you said you emptied the fridge and should of noticed if the light was on or not.
Circuit 5 = try one of the spot lights on the rear wall in front of the big back window.
Do any of them work?
Also jog the water pump, does it run?
Also just try the furnace?
Trying to figure out if you lost "all" inside 12 volts or a portion of it.
Do the lights or anything else work on shore power?
Knowing the answers to those questions helps narrow down the hunt. The 12 VDC power distribution system is the same for the battery as it is for the converter. The thing that changes is what power source feeds the 12 VDC fuse bank.
If the converter works the everything in the camper but the battery works nothing, this points to:
- The self resetting breaker out on the A frame died. Kitty had one corrode out on her.
- One or both of the green 30 amp fuses inside the camper in the fuse bank are loose or blown.
- The hot wire from the battery to the power converter has issues. (not likely, but not impossible)
- You lost ground between the battery and the camper frame. Odds are low but again not impossible
If you fell comfortable doing this, I would start with checking the lights and other 12 VDC devices in the camper. If everything is dead, I would start with the volt meter in the convertor panel on the big red and big wire wire looking for 12 volts. If that is dead, then go to the A frame box and sort out where you are loosing the 12 volts. If the battery has 13 volts, well it is not making it inside.
BTW the 30 amp fuse on the A frame is for the charge line to the truck battery. There is a self resetting circuit breaker in the box on the A frame that feeds the converter. Making an "assumption" your 2007 is the same as my 2004 was, here is what is inside that box. Does this look like yours?
Good luck and hope this helps
PS After thinking about Gene's thought, if you plug the 7 wire in the truck and the truck running and the camper lights run off the truck, then this points to the self resetting circuit breaker or even more odd, the disconnect switch. A volt check on the circuit break on the A frame will tell for sure. Just unhook the truck when testing.