Thanks for the advice. I pulled the furnace, and removed the combustion chamber. It looks to be in very good condition, very solid, and hardly heat tarnished at all. Also, the limit switch that runs through the gas valve line, is the only limit switch on the furnace. It shows no continuity between the posts.
The way this is wired, I would think it screws up the sequence of operation, as there will be power sent to the igniter board only thru the sail switch. I think the limit switch cycles regularly, anytime its calling for heat.
If power is sent to the igniter board thru the sail switch only, its going to try and light even if the limit switch is open. What happens to the 3 try delay??
I'll pick up a new limit switch and put the unit back together.
I was relieved to see the chamber in such good condition, considering this is a 21 year old coach. It would be nice to see the replaceable parts a little easier to access.
Steve