I have the same furnace. Since the fan comes on and you hear the click of the igniter, you have the breaker and thermostat on correctly.
For lots of detail on operation and maintenance see this:
http://manuals.adventurerv.net/Atwoo...nuals-2007.pdf
The normal operation sequence is as follows:
1. A timing circuit allows the blower to purge the
chamber (15-17 seconds)
2. The board supplies current to the gas valve and
causes it to open.
3. As the valve opens, the board sends a high voltage
spark to the electrode at the burner. The board
detects the presence of a flame. If the flame is not
sensed after approximately six seconds, the board
will lock out (three try for ignition, one hour lockout
and then three retry), shutting off power to the
valve.
4. If the system does not ignite and the thermostat
remains closed, the blower will remain on until the
thermostat is reset manually.
This forth step is code words for turn down your thermostat so the fan finally turns off since the furnace has not lit! Do not wait for an hour.
The likely problem is no propane at your furnace because there is air in the line. If you have not used your furnace this air has to be purged out. In my case there is an inside stove hookup beyond my furnace which I only use to purge the line. I connect my stove and turn it on trying to light it until it finally lights. Then I know propane is in the pipes close to my furnace and (almost to my fridge too).
Then turn up the thermostat and let the furnace try again to light. It may take two or three times, but it should light.
I was experiencing an issue where mine would light sometimes, but not other times. I decided to remove the igniter unit from the furnace and clean it. I carefully removed the screws and then slid out the igniter being very careful not to break or crack the porcelain insulator (see service manual). There is a small fireproof gasket that separated somewhat, but it seems okay.
I sanded the electrode tips and put it all back together. Now it mostly lights on the first spark.
Good luck