Propane Out or Battery Smoked?

[5picker]

Originally Posted by Scrapper

Not if the fan does not spin fast enough to close the sail switch.

Correct, I've experienced several times where the furnace fan run and I had lights but the voltage was low enough the fan didn't run fast enough to make contact in the sail switch.

Back to the OP... you could have had two issues. Low battery and the propane things that have been discussed. You may need to address both.

[Larry-NC]

Originally Posted by Thurman

LED lighting will work efficiently to the eye at something like 4 volts DC and I'm thinking that 9 volts is the furnace low voltage point.

The manual for the Suburban SF-xx line states that the voltage must be above 9.5 volts for the furnace to attempt to light.

Larry

[camaraderie]

Originally Posted by TexDave44

Gonna grab me a volt meter and have them teach me how to use it

May I suggest you get an AC/DC Clamp on Multimeter. It gives you the abilit to do the standard voltage and continuity tests...but also the ability to diagnose & monitor AMPS... as in what you are using and what you are putting back in when camping. About 50 bucks on Amazon. Like so
https://www.amazon.com/MS2108A-Range...+meter+dc+amps