Can't find any previous posts like this one. 08 f150 King ranch with 5.4 l. truck started fine yesterday morning and went to work had to go to the parts store in the day truck started fine again had to go pick up my son from the house to come help me work and in the truck started fine went to leave to go back to the job site and truck sounded like it was a dead battery but it started like the low slow cranking. Went to go home and then even worse on the low cranking and then eventually no crank all of the lights work fine even went and bought a new battery and put it in and no go swap relays and it didn't help anti-theft light seems to be fine I think there is power to all fuses except 7 8 35 + 36. Any help is greatly appreciated

 

Clean the cables at both ends. You just might have a bad starter but it's too early to know for sure.