The headlight went out on my truck last Thursday. First time on a six year old vehicle so no big deal. Anyway, I stopped at an AutoZone on the way home from work and asked for a headlight bulb for a 2001 Chevy S-10. They gave me a Sylvania series 9005.
Went out this morning to install said headlight before it got too hot out. Took the assembly apart, unplugged the old bulb, inserted the new one in the wiring harness and then went to refit the bulb into the headlight assembly. Didn't fit. I messed with it a bit, then pulled the assembly apart again and looked at it. The seal didn't quite match up on the new bulb. I looked at the tiny tiny numbers on the old bulb and saw that the old one was a Sylvania series 9006. Bingo. The wrong bulb.
Soooo, I have to go get another bulb later today and install it this afternoon when the sun is nice and hot. Yay. I'm not too mad though. I used to be an auto parts counter man. I'm sure his computer told the clerk who served me that the 9005 was the right bulb. Automobile manufacturers are notorious for changing parts in mid run on the line when they run out of something. Probably some of the S-10s do use the 9005. Just not mine.