2002 Buick Lesabre power

First check for multiple blown fuses under the hood and inside. When you don't use a memory-saver device, it is common for fuses to blow from the surge of the many computer memory circuits charging up. Not only have cars become unnecessarily complicated, even replacing the battery requires training now.

The colors just denote the current ratings. Yellow is 20 amps, red is 10 amps, etc. The square fuses with clear plastic windows on top can be a little harder to see sometimes, but the fastest way to test the smaller spade-type fuses is with a test light. Those fuses have two small holes on top for test points. Turn on the ignition switch, then test at each of those test points. You must find 12 volts on both of them on a fuse. If you find 0 volts on both sides, that circuit just isn't turned on. You're looking for any fuses that have 12 volts on one side and 0 volts on the other side.

If the fuses are all good, you'll likely be in for a trip to the dealer. There is no single computer to "reset". That was common on GM vehicles in the '80s and early '90s when they had a lot of Engine Computer trouble. Now there are dozens of computers and it's common for some to lock up when the battery is disconnected or run dead. That's a trick that was designed in to get you to go back to the dealer, and that is a much bigger problem on vehicles just a few years newer than yours.

Those are for the head lights, which are turned off. You found 0 volts on both sides of those fuses, which is okay. You're looking for any fuses with 12 volts on one side and 0 volts on the other side.