My battery reads over 12volt, somewhere around 12.5volts...and both things are connected, but nothing electrial works. If I get a jump when both batteries are connected together i get everything electrical back... and I can start it... and it will run but when i hit the brakes it dies and comes right back.
Is my battery dead? alternator? or did i just unhook some connection without knowing (other than the big battery terminal connections).
Thanks

 

Sounds like you have a dead battery and/or a dead alternator.

Take the battery out and take it to an auto parts store and have them check it. Most will do it for free.

Once you have a known-good battery in it, start it and take it to an auto parts store that will check your alternator output.

Then you know where you stand.

 

Just an update:
The problem was neither the battery nor the alternator... rather it was the connection to the battery. The postitive terminal connection was corroded/crap, replacing the battery and the terminals for both positive and negative fixed the problem.... replaced the battery too for good measure