I have a carrier air handler, only being used to cool a room - no heat. I unfortunately have no documentation on this unit and have yet to be able to find wiring online for it. Does anyone know what the 5 A fuse is for? is it 24v control voltage for my Tstat? This thing will work fine for a day or two, then pop. (don't you just hate intermittent problems?) I will double check the wiring, but did not find anything weird the first time around.