This is allegedly related to the Balmar relay system installed by Winnebago in the Ford Transit van.It is currently at the dealer, Colonial Winnebago, in Millstone Twp., NJ. Dealer can be contacted for inspection. We began traveling at a 25 mph speed for about 2 miles when smoke began to flow from under the hood. We pulled over to inspect; 911 was called. Smoke and flames under the hood were visible and continued until the fire truck came and extinguished the fire. Our safety and the safety of others was put at risk as the unit did not display any warning signs on the dashboard, there was a fire and smoke under the hood, we were in a public parking lot, and the unit carries 2 20 lb. propane tanks. Problem was diagnosed by our local Ford dealer, who stated that this is a Winnebago issue, as this was a Winnebago specific modification to the Ford. Unit was not drivable and needed to be towed to Winnebago dealer for service. They know about this issue - and have known for some time - but have not yet released the recall. We do not know at this time when the unit can be repaired. I do not know who has inspected the vehicle other than the Ford dealer and Winnebago dealer. No other warning signs or symptoms before the incident occurred.