My furnace is a Trane with a White-Rodgers 50A55-480 control module. I have been tinkering with it for over 6 months now. I have replaced the ignitor unit and also steelwooled the other unit on the other side. I used to be able to move all the wiring left and this would allow the furnace to properly with some tinkering. Then it would go out again. I have jiggled each wire independently to see if there was a short to no avail. My next step was to replace the two 5 amp fuses and to replace all fully insulated terminal clips. It worked for about 20 seconds and now I have nothing at all. The unit made a repetitive loud clicking noise like it was trying to fire up and now the blower runs (no heat) until I power it off. The control module indicates a thermal protection device open error (4 flashes). I removed the control module and then removed the sheet metal to get to the rear compartment. I cleaned everything I could get to without removing the blower fan. I then cleaned the swith mounted on the casing of the blower motor and replaced the terminal leads also to no avail. I read that this switch has a manual switch but mine is just has a round disk. Should I try replacing this now? I did notice that on the rear of the board on the control module it has a brown discolorization about half dollar in size but see no indication of burned up soldier points. I have now ordered a Write-Rodgers 50A55-843 on E-Bay because I can't deal with no heat any longer. Please help!