Dutchmen Trailer Lighting problems by year

I recently purchased a 1998 dutchmen 'four winds' travel trailer with vin: [[redacted]]. The lights in the trailer are getting too hot, in fact the bulbs are melting the plastic of the light lenses. I checked with the mfgr to make sure the proper bulbs/fixtures were present and they were. The mfgr suggests using lower wattage bulbs, but this is unacceptable since the only lower wattage bulbs that fit do not give sufficient lighting. The bulb called for is a type 904. I feel if these lights are left on there could...