I play Audible books through my aftermarket radio, in a '93 940, with a patch cable to aux. input on the front panel. When I plugged the PDA charger into the cig lighter today there was a loud hummmm through the speakers. It occurs even when the charger is not plugged completely in, and only the grounding connections touch the lighter (center pin hasn't touched the center connection). I tried 2 different chargers and 2 different PDA's with the same result. What could be causing this? Could there be a ground connection missing somewhere? It has worked ok previously, but it's been several weeks since I had it in this car. If the key is in position one (radio on) and the PDA plugged into the charger & radio, there is no noise, when I turn the ignition to position 2 (cig lighter power on), the noise starts. When I use the same charger in my 960 with a cassette adapter for the radio input, there is no noise.
Marlin