Welcome to the forum
I’m pretty sure your furnace is propane fired. The fan is electric (12VDC).
Let’s start with the simple stuff:
Propane- cylinders full or at least not empty? Are they open? Did you just fill them? If you just filled them then light the stove for a minute and try again, you can also turn on the LP side of the water heater to help purge air.
When the furnace fan kick on, go outside to where the furnace exhaust is and listen for any clicking (sparker) or any gas smell. Th ere are a few things that can cause your issue, we just need to eliminate them.
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2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.
Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.