The various flaps in the AC/H ductwork are probably vacuum operated. When you quickly press down on the accelerator pedal, engine vacuum falls and this is affecting the positioning of the flaps (blend doors). Some automotive systems have a small vaccuum accumulator to help carry through momentary drops in vacuum. For this to work, there is a one-way valve to keep the accumulator from drawing air through the vacuum line when the vacuum falls. This valve may be in the accumulator or in the vacuum supply line. It's not working or is missing. There may be ported fittings that are missing. Some of the vacuum lines are ported, in other words, an orifice is present to throttle maximum allowable flow. Often, the orifices are built into the various fittings. Therefore, if a broken fitting was replaced by an ordinary, general purpose fitting, the orifice would be missing. you'll need to consult a good repair manual to sort out where the orifices are located. If a fitting is described as a ported fitting, it has a restrictor built in. If the one-way valve is in the accumulator and it no longer works, replace the accumulator. The accumulator may be spherical and about the size of a softball. If there are serious vacuum line leaks between the accumulator and the blend door actuators, the supply system can not keep up with the leaks when vacuum reduces. A common leak is a bad diaphram in an actuator. Of course, if you pull a long grade, the vacuum will fall and the accumulator will exhaust itself and the blend doors will return to their "normal" positions. In this case, the engine may be overloaded (running full time at near open throttle). It needs a downshift to a lower gear to pull the grade. A general rule-of-thumb is that if the engine can not accelerate, it is "lugging" and needs a shift to a lower gear. Let us know what you find.

It's been 24hrs. Is a/c still running?

I never shuts down with temp setting at all ( both fan and outdoor unit) . " It never shuts off or indoor blower stops with outdoor unit still running, then you do need a new stat." One person on another forum suggested disconnecting the green thermostat wire . He told me that the control board was bad if it still ran . I tried that and it did still run. A thermostat is inexpensive and easy to get but I would like get it right the first time . Could ou please expand on this some more . Thanks

X-10 stuff is used to remotely turn lights on and off. http://www.x10.com/ Go here for a description of X10 http://en.wikipedia.org/wiki/X10_(industry_standard) This post was edited by Toolbelt68 on Mon, Oct 27, 14 at 6:19