There should also be a switch somewhere on or near the thermostat to turn the furnace off and on. You don't want the furnace trying to come on if the temperature drops while the unit is in storage, so there usually is a separate switch somewhere.
Also, even if the gas is off, the furnace fan will usually try to run even before the burner lights. I don't know about your 1994 model, but most newer RV furnaces have a forced air exhaust, so the blower must be running before the burner will even try to ignite. If the blower isn't trying to run, I suspect there is a switch turned off or a problem with an electrical connection.
2015 DRV Tradition 375KPS
2015 Chevy Duramax 3500HD LTZ Dually
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