I have a Hamiton upflow.. I replaced the Blower Motor and put system back together but now I am getting 4 flases inticating open limit switch? put new switch in but still getting 4 flases? Note: fan kicks in automatically indicating a cool down I think? tested continuity and all wires are good? There is a warning printed on the computer that if power is reversed system will sut down? All wires connected per digram, is there a way to reset system/computer. It appears to me that the computer is indicating open heat limit switch but all is good so the computer could have just gone bad..any help before I drop the cash for a new computer?