Carnut: I replaced the aspirator hose to the in car air temp sensor. If I place a lighted match directly above the in-dash temp sensor grill and blow the match out, I would expect the lingering smoke to be drawn into the grill. However this does not occur in my car! Is there a way to determine if the temp sensor system is operational? The system was retrofitted w/134 by the prior owner. The a/c operates modestly well (center vent out-put) 40deg in a 95deg ambient at a steady 65mph. The heating system operates equally well with 120deg output at the side vents. The system appears to cycle the blower properly in both heat and a/c modes. I removed the pipe leading from the temp sensor where it enters the blower motor area thinking the disintigrated foam may have blocked the air passage. The pipe is clear?