I have a Trane XR90 that was showing a solid diagnostic light. Could wiggle the wires and the furnace would work for a few hours. Solid light wiggle the wires and board = heat. Finally wiggling wouldn't work. So I replaced the IFC board. Went to turn every thing on and now 4 blinks on the light for a Open Temp Limit Circuit... Burners light and heat up for a minute, but the fan doesn't kick in. so,did the manual reset 2 x in 30 secs, no avail. Tried to reset the limit switch, but there is no "positive" clicking feeling, it moves but not sure it is right. Anything I am missing??

thank you