Two new batteries, now truck begins to start but then goes dead, then it does start. Climate control also resets itself. Why?
#1 Check if you have Spark,#2 Check if you have fuel Coming Out to your injectors.. Could be a Bad Coil Pack, or a Bad Fuel Pump
Check for codes there stored on the PCM (vehicles computer) borrow or buy a basic OBDII code reader. My shot in the dark answer is the PCM lost its KAM (keep alive memory) which controls idle function.. start it and let it idle / or try and keep it running with the accelerator so the system can relearn. So you replaced the battery 2 times? then the start and stall problem began ? finally may have a problem in the HVAC control module.
Looking for a Used Silverado 2500HD in your area?
CarGurus has 26,416 nationwide Silverado 2500HD listings starting at $2,500.
Search Chevrolet Silverado 2500HD Questions
Chevrolet Silverado 2500HD Experts