I have a AMC Hornet It runs like a million...

Dear Car Talk

Dear Car Talk | Apr 01, 1994

Dear Tom and Ray:

I have a 1972 AMC Hornet. It runs like a million and still looks good enough to make me proud. But there is trouble with the left turn signal. When the weather is warm, or it has been in the garage, it works fine. But when the weather is cold, the light comes on, but won't blink. I've had it to three garages, and none of them have figured it out. I have replaced the bulb, flasher, and fuse, and had the wiring checked. What do you suggest? P.S. I love your humor and wouldn't miss reading your advice!

TOM: We knew you had a sense of humor, Mary. You'd HAVE to have a sense of humor to say you're proud of a '72 Hornet!

RAY: Here's the story, Mary. When the turn signal lights up, but doesn't flash, that means that there's too much resistance in the circuit. A bad bulb is enough to increase the resistance and cause this kind of problem. But we know that it's not the bulb because you've already changed it.

TOM: So the next thing I'd check would be the bulb socket. It's quite common for a bulb socket--especially in an older heap like this--to get rusty and corroded. That means there's less metal-to-metal contact than there should be. And, as you know, when things get cold, they shrink. So the socket may be shrinking in cold weather and losing whatever good contact is left.

RAY: If that's not it, it may be a loose or rusted ground connection that's also being affected by cold weather shrinkage. Your mechanics haven't been able to find the problem because they've been working on the car in the garage, where it's what? Warm!

TOM: So here's what you have to do, Mary. Next time the forecast calls for six degree temperatures, leave the car outside your mechanics' garage overnight. The next morning, tell them to put on their Bronko Nagurski long underwear and take a test light outside and check out the circuit. It should be easy to solve. And I can tell you from personal experience, the colder it is out there, the faster they'll figure it out. Good luck, Mary.

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