I just bought a 2002 Chevrolet 2500 with 6.0 gas engine and a plow. Truck is in great shape body and running gear wise, however the previous owner told me that the battery will go dead if the truck sits for more than a day. The first time I went to drive it at night I quickly noticed that it had no dash lights. When I got home I checked the fuse and it was missing, so I replaced it. Within 4 hours the battery was dead. Because I rarely drive the truck at night, I removed the fuse and the battery seems to last a day or so without the fuse in. However, tonight while walking past the truck I noticed the High Beam indicator light, and the cruise control light were on. When I open the door they both went off. When I shut the door, they come back on after the dome light shuts off. This is with the Illum fuse removed. Anybody have experience with this sort of thing?

Well, it'* obvious that you have a parasitic draw. The first thing that I would do, would be to set up your battery with an amp meter and then start removing fuses to see which circuit is causing the draw. do you know how to perform a parasitic draw test?

Since the vehicle still died even with one fuse out it'* apparent that there is more than one circuit that has a problem.

1. Remove the negative side battery cable from the negative battery terminal.
2. Connect the black wire to the com input on a multimeter and the red wire to the 10A or 20A input on the multimeter. The meter needs to be able to read at least 2 or 3 amps for this test to work. Connecting the red wire to the mA input on the multimeter won't work and could damage the meter.
3. Attach a multimeter (set the dial on the multimeter to measure Amps as per multimeters instructions) between the negative cable and the negative battery post. Wait a few seconds to several minutes for the car to go into sleep mode — i.e. when you make the contact with the ammeter, the car'* computer systems "wake up." After a bit of time they will go back to "sleep."
4. If the ammeter is reading over 25–50 milliamps, something is using too much battery power.
5. Go to the fuse panel(*) and remove fuses, one at a time. Pull the main fuses (higher amp ratings) last. Perform the same steps on all relays found in the fuse panel. Sometimes relay contacts can fail to release, causing a drain. Be sure to observe the ammeter after pulling each fuse or relay.
6. Watch for the ammeter to drop to acceptable drain. The fuse that reduces the drain is the draw. Consult the owners' manual or service manual to find what circuits are on that fuse.
7. Check each device (circuit) on that fuse. Disconnect each lamp, heater, electrical device one at a time to find the drain.
8. Repeat steps 1 & 2 to test your repair. The ammeter will tell you exact numbers.

I have a 1997 Chevy Silverado that I had to change out the multi-function stalk because I had lost low beam on the headlights. Mine had a wire that was broken. Don't know about your truck but on mine the multi function controls signal lights, cruise, high beams etc. Go fishing under the dash and unplug the switch to see if the battery will live longer.

I recommend a more methodical approach. The chance of the OP having the exact same broken wire is very slim.

as stated above, definitely perform a parasitic draw test. very easy, and will give you a lot of information.

number one thing to remember, make the vehicle think it is "asleep."

one thing that i didnt see mentioned previously is to engage the latches on all doors you will be using to access the vehicle, including the hood latch. not quite sure with an '02 but especially with newer vehicles, any time a door is open the latch sends a signal to a module to tell the dome lights to turn on. that signal "wakes up" the module and in turn amperage will be pulled from the battery by that module and the dome lights giving you an incorrect reading.

best method in my opinion.

disconnect negative batt. cable
open all doors and use a screw driver to close the latches on all doors and hood. this will make the vehicle think all the doors are closed and the vehicle will go to sleep.
connect a multimeter between the negative batt. post and the negative batt. cable. set your multimeter to read amperage. best setting is 0.000 to get a single digit amp, and 3 digit miliamp.
when first connected, your multimeter will probably read between 2 to 5 amps (for example 3.541)
after all modules have shut down and the vehicle is "asleep" your amperage should be somewhere around 380 mA (0.380)
as each module goes to sleep you will see your amperage begin to drop.
once the amperage holds at a set amperage, you have your baseline.
begin pulling fuses one at a time and check your amperage.
if it does not change, that circuit is okay
reinstall your fuse and check your amperage, it may increase briefly due to "waking up" the module by re-inserting the fuse. wait for the module to go back to sleep and your amperage to drop back to your baseline.
continue with all fuses until you see a noticeable drop in amperage when pulling a fuse, then you will have found your proble circuit(*).

Good Luck!! - ElecTechChase