New owner of a 1995 Dodge 3500 Dually Diesel with 77,000 miles on it. Was told that the previous owner had put a shift kit in it for an in-bed camper. If it's cold, it won't shift into third for awhile. If you let off the gas, it will eventually shift. Not the real problem though. While pulling my 10,000 lb. travel trailer, the gauges started bouncing all over the place and the dash lights would flicker. The transmission drops 4th gear and will only run 1st gear through third. The tach will not work when it does this and the battery gauge shows below 14. I feel it is an electrical problem, but not sure. I cleaned the battery terminals and checked the batteries, but didn't fix the problem. The previous owner had extra ports put into the bed of the truck to plug his camper into. Don't know if this has anything to do with it or not. When the truck is first started cold, it works okay, but once it warms up, it starts doing this. Any help you can give me would be appreciated. Oh, its an automatic with the 5.9L diesel engine.