Goodman furnace not lighting
The two leads going into the gas valve should read 24 volts for about half a second just before it shuts off again if that's the case then your gas valve is no good. If you don't get 24 volts for half a second or so just before the igniter shuts off then the problem is Upstream. Possibly a pressure sensing device attached to the gas pipe doesn't allow the gas valve to open if the propane pressure is too low I don't think Goodman and uses that set up for propane conversions) you may have an issue with your circuit board. Often grounding will be the first thing people jump to, but in most cases a grounding issue causes trouble with sensing the flame. What would happen is the flame would light and then go out that's not the case here.