P0336 Crank Sensor Problems

[grandamcorning]

I have a 2002 Pontiac Grand Am 3.4 Auto. I just put a new motor in it and having problems with this P0336 code and comes up as a crank position sensor. So I changed the one on the back of the motor and light wont stay out. Changed the one behind the harmonic balancer and had to reset the balancer a couple of times and the light still wont stay off. Then I was told that it could be the camshaft postion sensor so I changed that and still the light wont stay off. I have no driving issues just problems with this light. I have checked the wires for burnt mark and rubbing marks and also tested the continuity to make sure power is going threw. The only problem I have is the battery wont stayed charged and the first time starting it up when the car has cooled down it wont stay running on the first attempt but will on second attempt. Any suggestions?