A Most Curious Array of Breakdowns

Dec 28, 2004


RAY: James Oliver from Portland, Oregon sent this puzzler to us. I'm not going to change too much. He seems to have grasped the essence of the obfuscatory narrative.


TOM: Great! All your work is done. You just read it.


RAY: His introductory note says, "This is a true story," and, then in parentheses he says, "Within the limits usually considered reasonable for puzzler content."

He writes,

"I drive a 13-year-old pickup truck, with over 220,000 miles on it. One recent, sunny, August afternoon I was cruising south on the freeway at about 75 miles per hour. After I got about five miles out of town, I saw a plume of smoke on the horizon. Traffic suddenly came to a dead stop, and a state trooper and TV news truck drove past on the shoulder. For the next several hours, I sat in stop-and-go traffic, mostly stopped, with cars just inching forward and then stopping.

"The dog day sun was shining through the front windshield of my car, but a nice breeze from the west was keeping the temperature in the cab bearable. After several hours, I saw two very large SUVs on the left shoulder. Both had their hoods up. On the right shoulder I saw a moving van and a large pickup towing a boat. Both the van and the pickup had their hoods up. About 50 feet further was a fancy German sedan, an Audi I think, with its hood up.

"I continued to see vehicles on the shoulders with their hoods up for the several hours, until we passed firefighters mopping up a brushfire, and traffic got back up to speed. Hours had gone by, by this time. I spotted the driver of the German sedan walking on the side of the road, so I asked him about his car. He told me that the engine just stopped and would not restart. He turned the key and it was dead as a doornail.

"I asked him one other question, and he answered, 'Yes.' It turned out that the other vehicles had the same problem.

"Why did the engines stop in all these vehicles?

"Here's a hint: My pickup didn't have this problem."
Answer: 
RAY: Here's what they all had in common, their batteries all went dead.

The reason their batteries went dead is that, unlike Jim's truck,
which didn't have an air conditioner, they were sitting there with
the AC on -- and they weren't moving.

The alternator charges the battery when you're moving. It's not
designed to keep your battery charged for three hours or four hours
at a time, when you're not moving.

The charging system wasn't producing enough current to keep the
battery charged and run the AC, which requires an electric fan to
cool the condenser, a compressor clutch, and a blower motor. Not to
mention, they probably had their laptop computers plugged in!

TOM: Don't forget the cell phone charger, and the 16-speaker sound
system, with the 150 watts subwoofer.

RAY: In fact, many modern cars also have their headlights on during
the day, including, in this case, the moving van, the SUVs and the
fancy Audi.

RAY: So who's our winner, Tommy?

TOM: The winner is Judith Cotes from Bellingham, Washington. And
for having her answer selected at random from among all the correct
answers that we got, Judith is going to get a twenty six dollar gift certificate to
the Shameless Commerce Division at cartalk.com. And with that
certificate she can almost get a brand-new Car Talk stainless steel
thermos.


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