now locate pressure switch. It has an rubber tube and 2 wires to it. Remove 2 wires, start furnace, wait for exhaust fan to start and touch the 2 wires together so they make contact and hold them that way and see if unit progresses.
I will be off line for a bit but will respond as soon as I get back
Here is a manual for your unit. - http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/58pa-1si.pdf
Frome here out the test require checking micro amps of flame sensor. If sensor test good replace circuit board. If sensor does not test good replace sensor
the sensor should read at least .5 ua. The meter set for DC micro amps, one meter lead to sensor and other eter lead to where sensor was plugged in. If .5 and above replace ign control. You can also add a wire from the burner to the ground terminal on the control
We do not have the furnace working yet but Billy went out of his way to help. We still have something to try that he gave us. My husband wants to make sure Billy receives compensation for all his help. I think the last thing he did was getting us the manual for the furnace. Which may still hold the answer to the problem. We are pleased with the service we received and will recommend the site to others, or use it again for any further problems. We were not able to work on it today and will not work on it on Sunday. If there are further questions we will contact the service on Monday.
Thank you for all your help