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Why is the fan running in Brad's car, long after he's done driving? Auto-poltergeist... or something more earthly?

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Dear Tom and Ray:



Last night, my neighbor knocked on my door an hour after I got home. He asked me if I had left my car running for a reason. I told him that I had turned off the car and had the keys in my pocket. He said, "Well, your fan has been running for an hour or so, and real loud!" He was right! I put the key in, turned it to the "accessory" position without starting the car, and then switched it back off. The fan finally stopped. Sadly, the car would not start the next morning without a jump. Two to three times during the past three months I have returned to my car in a parking lot to find the stereo playing while the key was still in my pocket. Clearly, some switch is staying connected when it should be off. Is it part of the ignition switch? Where should I look first? Thanks. -- Brad

TOM: Look to the ignition switch itself, my boy.

RAY: I agree. If it had just been the fan, I might have suggested a faulty fan timer, or something like that. But when you threw in the fact that you come back to your car, and it's listening to Jimmy Buffett all by itself, I think it has to be a bad ignition switch.

TOM: It's allowing accessories to draw power from the battery without the presence of the key. It's acting as if you left the key in the "accessory" or "start" position, even though you didn't. And that's what killed the battery.

RAY: Have your mechanic test the ignition switch. He'll do that by unplugging it while the fan or the radio are misbehaving. I'm guessing a new switch will solve the problem, Brad.

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