I can't try the water heater at this time. It is 10 degrees outside. I just went outside and turned off the lp tank and slowly turned it back on. I turned the furnace on and sat outside listened to the furnace run. When I turned on the furnace, the fan came on immediately. After about 5 seconds the burner came on but it sounded like the flame slowly went out, it came back on and slowly went out again. It sounds like the gas flow is not steady. I tried again with the same results. Another time I had the stove burners burning and did not notice any difference in the stove burners while furnace burner was running. I will crawl under the camper tomorrow and see if the furnace gas line is pinched.
I will get a different lp tank tomorrow and try again.
Thanks for the suggestions everyone.