Where do I look to find the fuse that is open?

Maybe in your circuit board

Can you give a little more info on your problem. Are you looking for a fuse on the low voltage (24v) side of controls, or a main power(120v) fuse?

I`m just guessing he has a blinking led code saying open fuse,, I`ve ran across one or two,but can`t remember the brand of furnace that does it

It is right next to the red blinking light, I have the same problem, I need to find what is blowing the fuse. I get the rapid flashing led when I try and get the code