I have a carrier FB4BNF030, My blower seems to work fine while in the heat mode, but nothing in the cool mode. I recently replaced the outside power shutoff for the A/C, thinking that was the problem, but it still don't work. The outside unit comes on compressor, fan... Fan doesn’t run in the on mode, doesn’t run when jump to the "G" wire. Can anyone give me some pointers?
if you jump R to G on the board or off the subbase the hi speed winding is shot on the furnace....if you get low/med on the heating mode those speed windings and the cap are good....check the motor for a medium speed wire off the motor tag to get you thru the fall cooling if you need it...note the relay board might have 2 different relays one for LO fan heat and another for HI fan cool