changing fog lamp bulbs

Wouldn't be terribly unusual; halogen low-voltage bulbs operated on a common electrical system tend to have extremely similar lifespans (dying within hours or days of each other is not at all uncommon). This is especially true if you use your fog lamps a lot -- i.e., if you live in an area with a lot of fog and have reason to use them frequently, or if you're one of these who insist on driving with your fog lamps on all the time, even when there's not a hint of fog within 50 miles.

Which "bulb website" told you that? Master US bulb application data has it as an H3 -- not the same at all as an 893. Master application data is occasionally incorrect, but there's a ton of garbage bulb info out there, so it matters which "bulb website" you were looking at. Hope you weren't tempted to buy any of this ultrablue/superwhite/silverbright/etc. type crapola.

Tends to lend support to the H3 theory -- GM continues to pretend bulbs that have been common throughout the world since 1965 (like the H3) are very special, rare and hard to find items.

Because they are mounted down low where rocks tend to take 'em out.

DS

If you're not sure they are bad why not check the socket for voltage?

Remove one of the bulbs and look at the filament . If there is a break in it , replace it . The type number should be printed at the base of it . I get mine at Walmart .

Sometimes a break is visible, but not even close to always.

Thanks, good point...

Or/And put test leads to put 12 volts across the bulb terminals.