• You heater problem is isolated between the heater fuse and the circuit board.  This problem is relatively easy to resolve, make sure the fuse is good, then make sure the fuse holder is clean, blow out the fuse holder with canned or compressed air, and make sure the fuse holder is good, if all is well there, then make sure your connection to the board from the fuse holder is intact and there are no lifted traces on the board between the 8 pin Molex and the fuse Molex connectors . this will resolve the lack of heat problem.