When starting the pickup it sounds like the battery is not charged. Slow crank but the truck has continued to start. Replaced battery, cleaned terminals and a couple days later---same thing?
Check your serpentine belt and tensioner for proper tightness and performance. A frozen belt tensioner will allow the belt to run loose and slip, reducing the alternator ability to charge the battery. Also check to be sure all the lights such as glove box and interior are off. Its easy to turn on interior lights with teh dash light dimmer and not realize it. If all this checks ok, drop by your local Advance or Auto Zone and have them perform a complete charging system test. If its not a loose or slipping belt it is an underperforming alternator, failed diode trio or a parasitic amperage draw draining your new battery. Good Luck!
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