Hi - we have a 2001 Acura MDX with a peculiar problem that actually occurred previously but went away on its own. When we turn the vehicle off the HVAC continues to run and the heated seats stay on. This happened last year during the winter (I remember because the heated seats stayed on then as well). I discovered the problem last year after a battery drain. This year we noticed before the battery drain and I am able to preserve the battery by turning the seat heat and the HVAC completely off. Last year the problem went away after a couple of days before I could get to a mechanic or troubleshoot it myself. I expected the problem to reoccur so I could more easily trouble shoot, but it didn't reoccur until now.

Thoughts on what could be causing this problem? Ignition switch, perhaps? Is there an easy way to test for that or ideas about other potential problems?