Suburban SF-30

[jregalia11]

No heat. Now I have watched you tube videos.. repaired the furnace once before and this time I am stumped.
I have a furnace that will bring the blower on,purge,then NO spark and then open the gas valve.
I have a new board and new spark igniter installed to eliminate a failed old part. Not a parts replacer but there can only be 3 things really wrong.
Maybe someone can help me.
I have made sure spacing is correct on the spark ignitor. 1/8 inch and also shined the light into the burner to line it up. Checked 13vdc. Now I am not getting any bolts of of the board where the spark ignitor is.
My last guess is the sail switch but... before I order one as a guess... correct me if I’m wrong and that the gas valve would not even open if the sail switch or high temp limit was OPEN. I do know the sail switches are the most common failure tho.
Btw have gas.. and gas pressure is proper.
At least it appears that way with other appliances.
No tick tick tick before the gas valve opens.

Searched for this issue before so sorry if it’s a repost but no one seems to ultimately ask the question... will the gas valve open even with a failed sail switch ? I don’t think so from what I have read but I could be an idiot. Ha.

Thanks in advanced.