When I bought my truck it was already 10 years old and it had an aftermarket radio installed. It was summer when I bought the truck so I didn’t discover the minor flaw that it has until spring. The radio overheats and shuts off if the air conditioner is not running. The air conditioner vents run on either side of the radio and they kept it cool and running well all summer long. During the summer months, I never drove the truck without the A/C running as well. When fall came, I turned off the air conditioner and drove with the windows open and the radio shut off. When I checked it, it felt very hot to the touch. I turned the A/C back on, waited awhile, and the radio worked again. Since then, I have discovered that running just the vent on low is also sufficient to keep the radio cool. Running the heater in the truck is not. So if I want to open the window, I need to make sure that I keep the vent air going too. If I want to run the heater, I can’t use the radio. This is all very annoying but I don’t want to take the dash apart to replace the radio. It just reminds me of computer rooms that are kept extra cool, with strong air conditioning, so that computers don’t shut down in office buildings. Except, this isn’t an office, this is a truck. Oh well, I guess that’s what you get when you buy an older used vehicle: there is always some glitch of some kind.