Andrew If the car voltage drops that much you may have a bad battery or a battery that is very run down. Batteries take a lot more time to charge than people think. The alternator could be weak also. If the battery is not 12.6 volts at all systems off, then it is bad or under-charged. It could also be that a ground is not good. There is the cable ground from the battery of course, then the ground strap at the motor mount, and the really troublesome one on the frame going to the central ground connection in the connection box in the engine compartment and coming out in the car behind the backboard above the relay compartment. The positive cable and/or wires could be troubled connections too. You will find it eventually. Keep testing. Harold McElraft - 3354 For the > time being, though, the AC clutch seems to be staying engaged almost all > the time it should. It's sometimes not holding when the engine drops to > idle, but it grabs again as soon as I start moving. > > -andrew > #4115 > Houston TX