I hate to say it, but sometimes you got to call in an expert.
Knowing when that point arrives is half the battle.
While we try to be of assistance we can't be there looking over your shoulder and in reality very few here are "experts;" just campers just like you with varying degrees of experience.
In the end, it is your camper. You should be camping and not fussing with the furnace. Once you hit the limit of your experience; and then ours; it is time to haul that puppy to a service center. Look on the SUBURBAN (or your furnace's manufacturer's) web site for your closest repair center. It may well be your dealer, but in my case it was literally across the street for my Dometic refrigerator.
Remember you are dealing with propane and a misstep can be catastrophic. That is not to say you can't fix propane systems yourself, just that you need to know what you are doing to be safe at it. Once you pass your comfort zone; call in an expert. Just Sayin'
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW