One problem related to dash wiring has been reported for the 1999 Chevrolet Astro. The most recently reported issues are listed below.
With no one in the car, leftside door, the switch that controls the outside mirrors started on fire. Luckly I was near the car with a friend and saw the running lights on the car flashing and the door switch on fire. By pulling the battery cable off we stopped the fire. The drivers door and switch where burned. The car drove home. On the way to work the next day the car headlights came on and wouldn't go off, then the heat motor started going on and off. I left the car with norwood motors to check out under warranty. My days may be off a day or two, but after a few weeks the service department could not find the problem and just replaced the main wire harness. Because it was a fire the dealership told me it was not covered under warranty, and I had to use my car fire insurance. I am still blowing fuses 20 amp fuses to this day, I am very experience in the field we are talking, I personally I beleive the door locks which are the 20 amp fuse, is back feeding to the low amperage switch and feeding back and burning wires in the harness. I've saved the orginal harness. This problem can be solved with diodes that only allow the current to flow one way. Children in a car with no keys can cause this a condition. This is not a fire accident, it's a wiring design that needs updating. I couldn't get anywhere with Chevrolet, or the chevy dealership, because it's a car insurance problem know. So I am working my way insurance departments, and not the Chevrolet, which puts me in the middle with no support. I hope you can help. Thanks for your time james reyolds.