Last weekend I found the battery completely dead on my 1991 K1500.
Charging and testing the one-year-old battery showed that it was okay.
A possible clue is that the display on the heater/AC controls stays on
after the ignition is shut off and the key removed. (This started over
a year ago, although it never ran the battery down before. I found that
hitting the "recirculate" button would turn off the display.)
The heater/AC module buttons had been flaky for a long time, so I
replaced it after the battery problem. The display on the new module
still stays on after the ignition is turned off.
A friend has suggested that the control module on top of the steering
column (activated by the ignition) might be the problem.
I pulled some fuses and checked for voltage today, and found some that
showed about five volts. That makes no sense to me; seems like it
should be 12V or 0. Unless they're phantom voltages that show on a DMM
but wouldn't appear on an analog meter.
Any suggestions on ways to narrow this down would help. Thanks.
Warren Block * Rapid City, South Dakota * USA