The gas ignition fail light may come on momentarily when you first switch on the LP switch. Don't be too quick to shut the switch off. The switch does not directly open the gas valve. The gas valve is opened after the igniter comes on.
Bob & Joan Alexander, 2010 Tiffin Phaeton 36 QSH, 2013 Jeep Wrangler (toad)
Lobo & Juniper (woof, woof)