Find your DC Distribution Panel........usually part of the AC Distribution Panel
DC Fuses for lights, control circuits of fridge/water heater, furnace.
The fuses are probably not marked so you will need to test them.
Also check the light fixtures...may sure the on/off switches on the fixtures are ON.
By 'outside' lights I take it you mean porch/scare lights and not trailer running lights.
If running lights.they only work when hooked up to tow vehicle.
IF it's the trailer running lights post back for more info.
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31