Hi,

Here's one that's NOT in most of the books: if the connector's not
mechanically damaged (broken wire, cracked housing, that kinda stuff), a
"usual suspect" is corrosion, so many old time mechanics I've known kept
a jar of Vaseline on the shop bench and smeared a light coating on the
metal surfaces of the bulb and the contacts in the bulb holder when they
replaced bulbs. This helps slow corrosion, and often makes removal of an
old bulb easier. (If your contacts are corroded, and you've got the
older style holders where you can actually get to the contacts, be sure
to scrape 'em clean w/ a knifeblade or bit of sandpaper before putting
the bulb back in. Auto parts stores have spray cleaners for electrical
apps that help w/ the newer "push in" style where you can't physically
get to the contacts very well.)

Because a handful of diabolical engineers have been doing their best to
make today's bulbs hard to get to, a "stuck" one's sometimes a real
challenge to remove (esp. the all glass style that just pushes into the
connector instead of using the traditional metal bayonet mount), and the
auto parts stores sometimes stock a "special" bulb grease to help solve
this problem. It's probably rebadged dielectric grease, which sometimes
seems to work better than Vaseline on the "push in" bulbs (probably cuz
it "stays put" better in hi-temp locations?)

Plain ol' Vaseline is also as good on battery terminals as any of the
"special" lotions and potions I've tried over the years, so you might as
well make a party of it now that it's Fall and you're disassembling the
car anyway, and check your battery and clean/protect its connections.

Another of those "old school" things, eh? :)

Rick