Thought I fixed the problem but once again my truck will not start. I just recently got a new battery. It's maybe 2 months old. Was working great till about 2-3 weeks ago it would not start. All the electronics worked but the truck just wouldn't start and it made this humming sound. Of course it starts right up when given a jump. Fixed it about a week ago. Checked my wires, cleaned up the terminals with a wire brush ect. Got it running for 6 days at least. Was going to take it today to an autoshop to get my cat replaced. Damn thing wouldn't start and made same sound. Any ideas on what else it could be? Did Costco give me a shot battery?

 

Did you try the bypassing-the-starter-relay-trick? do a search on it. what happens is the contacts get weak and the battery doesn't have enough juice to get the starter going because it goes through the relay instead of getting power directly from the battery (or something like that). it worked for me..no more random non-starts.