What could burn through 4 distributors?

Dear Car Talk | Mar 01, 1993
Dear Tom and Ray:
Russ
RAY: Well, Russ, when you go in for another rebuilt distributor, don't send back the old one until you actually have the new one in your hands. That'll rule out the possibility that they're simply re-boxing your old ones and sending them back to you.
TOM: Actually, it's unlikely that you'd get four bad ones in a row, and that they'd all work fine for a month. So the more likely explanation is that something is causing the distributors to burn out. And my guess is that your alternator is intermittently over-charging.
RAY: That's different from what we do at our garage. We over-charge ALL the time.
TOM: If your charging system is occasionally sending too much voltage to the distributor, that could definitely fry it.
RAY: So have your mechanic check the charging system. And even if he doesn't find anything wrong, ask him to replace your voltage regulator. First of all, that's the most likely culprit. And second, they're probably getting bored changing distributors and would jump at the chance to do something a little different.
Russ
RAY: Well, Russ, when you go in for another rebuilt distributor, don't send back the old one until you actually have the new one in your hands. That'll rule out the possibility that they're simply re-boxing your old ones and sending them back to you.
TOM: Actually, it's unlikely that you'd get four bad ones in a row, and that they'd all work fine for a month. So the more likely explanation is that something is causing the distributors to burn out. And my guess is that your alternator is intermittently over-charging.
RAY: That's different from what we do at our garage. We over-charge ALL the time.
TOM: If your charging system is occasionally sending too much voltage to the distributor, that could definitely fry it.
RAY: So have your mechanic check the charging system. And even if he doesn't find anything wrong, ask him to replace your voltage regulator. First of all, that's the most likely culprit. And second, they're probably getting bored changing distributors and would jump at the chance to do something a little different.
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