Something is draining the battery on my 2000 Jeep Wrangler. We have a new battery, alternator checked okay, new starter. The jeep starts, lights come on, and then will die while driving. What could be draining the battery? Thanks so much.

Put a volt meter across the battery terminals while the vehicle is running. You should read no less than 12.5 volts at idle with no accessories running and no less than that with accessories all on. Normal volts should be around 13.5. Aside from slight fluctuations, the voltage reading should not steadily drop, regardless of how long it is running. I doubt if you have a system drain if it's shutting down while driving...the alternator would compensate for that. Some charging systems incorporate the voltage regulator into the computer. If the alternator checked good by itself but the tests I recommended show otherwise, likely your problem is with the computer.
If the engine does not need to be jump started after it shuts off, you may be looking entirely in the wrong place...but you didn't mention that part!!

Had similar problem believed related to my horn not working. It appears I have a bad clock spring in steering wheel, and it seems possibly shorting out causing my horn relay to be constantly energized, even with jeep off, (found this out by checking wiring and horn went off). since horn hasn't worked (clock spring), I removed my horn relay, and discovered my battery no longer drains.

Test the alternator charging capability by connecting a volt meter to the battery terminals and starting the engine. The voltage should be at least 13 VDC.
If it's less it will not charge the battery enough.
Hope this helps.