Borrowing from another thread, are you sure the brake light switch isn't sticking? If truck is outside and you don't walk behind it, you may not notice the brake lights. Other than that, as mentioned, set up with meter to check current draw and start disconnecting suspect items
one at a time until draw quits. All that being said, I have a vehicle right now with a NAPA battery that is a year old I suspect is going bad. I will get around to taking it back to NAPA to check the day after it strands me...
