Rambler's Alternator Light Mystery

May 12, 2001

RAY: This was sent in by a fellow named Roy Harvey. Roy says, "The year was 1971. The car was a '65 Rambler Classic with power steering, power brakes, automatic transmission, six-cylinder engine, and no air conditioning. In other words, my parents gave me their old car.

"The year and the car aren't important, but there are some cars for which you couldn't have this particular condition. It had about 80,000 miles on it -- and let me tell you they were hard ones.

"I was driving to school. About halfway through a 15-mile trip, the alternator light came on. It was daytime, so the headlights were off. The heat and blower were already off. I turned off the radio, but the light persisted. I began to worry. I then turned on one control on the dashboard -- and it wasn't the ignition. The alternator light went out.

"This told me what the problem was, and I continued on to school without concern. I later fixed the problem with a few simple tools."

Here's a hint: As far as I know -- and I know but Roy didn't know -- this switch actually had no direct electrical connection at all. In other words, it didn't have any wires hooked up to it.

Answer: 

RAY: Here's what he did. In -- lots of cars are set up like this -- he moved the heater control valve, which has connected to it at one end a little lever you move ...

TOM: Yeah.

RAY: And at the other end, connected by a cable, is a valve which allows water to pass from the engine to the heater. And when he did this, the water pump, which had been causing a slipping belt, all of a sudden had so much less drag on it that the belt, which was slipping and causing the alternator light to come on, went off, because now the belt was not slipping because he had reduced the ... the pressure in the flow, just ...

TOM: Oh, no. Bogus. Oh, bogus.

RAY: Every week I struggle to come up, and what am I met with? "Bogus"?

TOM: No, boooo-gus. But we do have a winner. We got a guy named Dr. James Randolph.

RAY: See? See? See?

TOM: He's a doctor. James Randolph from Long Beach, Mississippi.


Get the Car Talk Newsletter