Goodman GMS90703BXA Heater/AC - 3 Amps Fuse blows

It is a problem on your low voltage side. I had the same issue and found that my wire going to my outside condeser had been snagged on a wire hanger in my basement and was shorting out the system. I went a head and replaced the entire wire from my outside unit to my indoor and haven't had an issue since. So my advice is go to HD or Lowes and purchase some 14 gauge wire and replace the low voltage wire. If that doesn't work, then replace the thermistat wire, and thermistat. Great time to upgrate to a energy efficient thermastat.

This fuse is used on the low voltage side of the furnace. All 24 volt controls operate thru it. You may have a short in your thermostst, thermostat wire or even a bad transformer. After replacing the fuse, inspect the wiring in the cabinet as well as the wire heading toward the thermostat for damage. If you find none, check the thermostat for loose wires or contacts. If all else fails, jump out R and W with a small jumper temporarly at the furnace and see if the unit runs. You will have to tape the door switch closed to run it with the panel off. Remember, this will keep the furnace running 100% of the time until you disconnect the jumpers. Not a solution, just a test! If it runs flawless, you have a bad thermostat or wire. Diagnosing a transformer is for a technician.

I HAVE THE GMPN 0804 AND IT CAME ON THIS MORNING AND THEN A LOUD NOISE CAME OUT OF IT. I IMMEDIATELY SHUT OFF THE EMERGENCY SWITCH. AFTER A FEW MINUTES I TURNED IT BACK ON AND IT KICKED IN BUT THEN IT MADE A CLICK IN THE FAN ON THE BOTTOM WHICH DID NOT KICK IN AND SMELLED A LITTLE.