ive got a 89 jimmy fullsize 355 injected new battery new alt chargeing good according to all the tests ive runn but yet i can run it for five min shut it off and it wont start du to drained battery also if i drive it i can drive for 20 mins tops then it dies battery dead ive tryed numours batterys and alts replace ground and power wires same thing every time ive called shops and there stumped hoping some ones had this issue and sorted it out any help would be great

 

mmm do you have an alarm system? or sound system? cause if not set up properly it could drain it....

 

it does have a stereon but it was one of the first thing i disconected the drain is only with key on and running
no alarm