First, on all RV furnaces, the blower comes on first and runs for several seconds before the furnace ignites. This is to purge the system of any excess propane. The first thing to check is the off/on valve on the propane regulator. You should be able to access this throught the outside cover. Make sure it's on. Next thing to check is your voltgae going to the furnace. It if it too low the furnace will not light. If the DC voltage is good, there are several safety features built in starting with a sailswitch that will not permit ignition if the air flow in the furnace is too low. Assuming you have enough air flow the next thing you should hear is the ignitor trying to light the propane flame. The furnace will try to light 3 times, then shut down if the propane doesn't light. Set the thermostat to gas heat, then get up against the air intake and listen for the ignitor to try to light the propane. If it dosn't try, there are many potential problems, including the control board, alignment of the ignitor, or the ignitor itself. If it trys to light but doesn't, you may have to try it several times to get the air out of the propane line going to the furnace. Is it still doesn't light I would suspect looking in the propane control valve area. I would first remove the positve feed to the solenoid on the propane valve, and connect a voltmeter to it and to ground. Cycle the furnace and see if you have the proper voltage is feeding the solenoid. If you have voltage, reconnect the wire and cycle the furnace again. See if you can hear the solenoid activate the valve. if no, the solenoid could be bad. If you haven't resolved the problem, I think the next step is to remove the furnace where you can put it on a bench, and continue the diagnosis. Good luck.
Jim and Lynda, (Sophie, Jake, attack trained killer Shi-Tzus :-))
2003 Fleetwood Expedition 38N 2005 Saturn Vue