Hello, I have a Goodman furnace GMPO75-3, and a few days ago it just blew cold air and the red light blinked 4 times. This told me that the open limit switch might have a problem. So I turned off the power and removed the switch from the wall, after unplugging it and inspecting it a little, I reattached it and turned the power back on. It kicked right up and a started to blow hot air. So I turned it off and put it back together and now I'm not getting any power what so ever. The breaker isn't tripped, I have been told that it might be somewhere in the board, but that doesn't really help.

Please Help

Inside the panel you took off to get at the interior of the furnace is a chart that tells you what 4 blinking lights means. Its all codes and each color light and # of blinks has a different meaning. Can you find this chart on the panel?

I have, 4 blinking lights means open limit switch. But now after I got it to work all of a sudden it just stopped and now there is no power and no light.