A goodman furnace. Starts up with the induction fan.. and runs good, then electronic ignighter glows and the gas valve opens , then gas lights and system runs for about 10 seconds, then when the blower kicks on but everything else shuts off except the blower , I thought it was the PC board so I replaced it with no change to operation. I also replaced the flame scensor.. nothing. I then tested startup amps on the blower and got 11amps on start up. I tested the unit in AC cool mode and blower runs fine... with No shut down.. all safety scensors are good and not infuencing the PC board. I have a feeling that the run capacitor and maybe motor too are pulling too much amps (AT LEAST ON STARTUP) in the heating mode and triping the PC somehow.. help

I guess that would be possible about the run cap but that would be a very strange thing to happen.

I would check all the grounds from the electric panel to the furnace disconnect switch and then from the switch to where it attaches into the furnace.

The furnace needs a good chassis ground for the electronics to function properly. I suggest you loosen up all grounds then retighten them so they are proven tight. While you are in there you might as well check the white neutral and hot legs for tightness also.

A different person posted he replaced almost all parts on a Goodman and I told him the same thing I am telling you. He posted back that the ground in the furnace disconnect was loose and tightening it up solved the problem.

He said he felt kind of bad because he spent all that money for new parts and it ended up being a ground. Also check any grounds to the circuit board.

I would also check to see if the pressure switch is opening shortly aflter the burners ignite. Then you are looking at a venting issue.