Blazer has been running fine until this am. Went out to start it and nothing, dead, hooked it up to jump it off and it would start and then cut off as soon as the jumper cables were removed. I went and bought a new battery and the same thing happened, dead, jump it off it starts right up runs for a few seconds and dies as soon as cables are removed. It is getting no voltage at all, with new battery power door locks or windows will not work. Blazer has a new fuel pump, so I don't think this is the problem, can here the fuel pump click on when it starts. The security light will flash for a sec or two when it is running ( with the cables attached) then it goes off. Any suggestions??

 

check the cable from the alt to the battery or just run a new one

 

Did you have the battery tested before you replaced it? Pull the alt and have it tested, as well. It's only a few bolts.

 

check the cables as stated before it may be that alt but its juicing that battery to where the locks dont work im not so sure