I have a 2003chevy tahoe ive had it for about a year kept maintence up and everything. So like a month ago my battery kept dying wasnt sure y i got my battery tested my starter and alternater teated not one of the three was bad so i yook it to a mechanic and he fixed it he said all he did was tighten the negative wire so it happened again yeaterday i tightened the wire and got a jump it turned on normally but i came inside to get my kids and it didnt wana turn back on what can i do i do not have money right now so any ideas on what i can check for now would be great

 

I'm not sure what you meant by just "tightening", but, that doesn't mean that you have a good connection (positive or negative).

You need to get a Circular Wire Battery Terminal Brush, knife, and anything else you'd need to take all the negative/positive terminals apart, scrape/clean till they're bright as fresh silver, and THEN tighten them securely. Also, there are several other ground wire/straps located around that should be "maintained" as well.