All right, guys and gals, here's a good one. Ideas anyone?? This, on a 2004 Chevrolet Silverado Z71 Extended cab. The Truck has over 200,000 miles and seems to running like a top. Here is the issue: This only affects the left hand blinker. On occasion (Not every time I use the left hand blinker), my left hand blinker will "freeze On". The blinker symbol on the instrument panel will show the blinker on, but no blink. Other times, the blinker will blink fine UNTIL I apply the brake. Then, the blinking stops, and the brake light is on. There are other occasions, where I apply the brake, and the left blinker symbol lights up on the Instrument panel. Weird, I know. I can also turn off the blinker if the brakes are applied (and causing the blinker to stay "stuck on"), and turn the blinker back on and many times it blinks correctly. Anybody else seen this? The blinker and the brake light are two seperate bulbs if memory serves. There doesn't seem to be any commonality there. I do have the factory trailer towing package on the truck. It has been on there from the factory. This is a intermittent situation. It seems to do it MORE, AFTER the Truck has been running a while. So, that would be the first issue. The second issue, PROBABLY easier to solve. Again, an intermittent deal. On many occasions, when I turn off my Truck and exit through the driver's door, The truck does not see the door open. The cab lights do not come on, and the radio remains playing. This happens on occasion, also when entering the Truck. I open the door, and there is no light. I realize there is some sort of switch somewhere. I don't understand fully, where that is. The passenger door will also do it every once in a while. I wonder if ALL these electrical gremlins might be related. Some sort of bad ground perhaps? El Nino (haven't used that as an excuse in years, LOL). Any insight you folks have would be most appreciated.