My Lennox Furnace G41 Series keep blowing the 3 amp fuse on the printed circuit board

Furnaceguru
:cool:

Look for a short in the low voltage wiring or test/replace the board. You might look on the back side of the board for burn marks

Does it short when ac comes on?
Can you turn fan on and not short the fuse?
Careful checking the board... fingerprints can damage the board if it is not already damaged.
Also check the t stat wiring around the unit and make sure nothing has chewed through it or it is not showing copper anywhere.