What could cause Charles' headlight to blow... over and over and over again? Find out.

Dear Car Talk | Jan 01, 2007
Dear Tom and Ray:
TOM: Well, the first thing you've got to do is buy stock in Sylvania. It's making a fortune selling you light bulbs.
RAY: I think you have some water in the fixture, Charles. We see it a lot. You replace the bulb, but the plastic lens that protects the bulb is 300,000 miles old and has small cracks in it. When you drive in the rain, water gets in, and it can't get out.
TOM: It might not be easy to see the water, but my guess is that the bulb heats up, a bump causes the water to slosh or spray, a drop or two hit the white-hot bulb and kaplow! The bulb shatters.
RAY: Have a closer look and see if you notice any moisture in there.
TOM: Or goldfish. Swimming goldfish are a sure sign of the presence of water.
RAY: And then replace the whole headlight fixture. You can buy aftermarket fixtures for relatively little money. I think that'll solve the problem, Charles.
TOM: Well, the first thing you've got to do is buy stock in Sylvania. It's making a fortune selling you light bulbs.
RAY: I think you have some water in the fixture, Charles. We see it a lot. You replace the bulb, but the plastic lens that protects the bulb is 300,000 miles old and has small cracks in it. When you drive in the rain, water gets in, and it can't get out.
TOM: It might not be easy to see the water, but my guess is that the bulb heats up, a bump causes the water to slosh or spray, a drop or two hit the white-hot bulb and kaplow! The bulb shatters.
RAY: Have a closer look and see if you notice any moisture in there.
TOM: Or goldfish. Swimming goldfish are a sure sign of the presence of water.
RAY: And then replace the whole headlight fixture. You can buy aftermarket fixtures for relatively little money. I think that'll solve the problem, Charles.
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