I've got a 92 740T wagon. First question is I just replaced the ac/heat controls in the dash as the old was bad. Now when the compressor kicks in the car lugs down at idle a couple of hundred rpms and idles horribly. Otherwise it runs fine, gets good mileage etc. It did this somewhat with the old controls when working but seemingly not as bad. Would it be possible if the vacumn lines on the rear of the controls were hooked up wrong (not sure if this is possible, and I don't think I did), would that create this problem. Also the cruise control works correctly under 60mph sometimes, over 60 it kicks in then proceeds to gain 5-7mph before disengaging. There have been a few times it hasn't engaged at all regardless of speed. Any ideas. Thanks in advance.