@mef0629
Quick tip for electrical diagnosis....
Charging System -
1. Idle truck, put multimeter on battery to see battery voltage while idling. You want 12.5+
2. Raise idle to 2000-2500 then check multimeter, you want to see over 13.2-13.5 ideally if system is charging. If not, you have a voltage regulator/alternator/battery/wiring issue.
Parasitic draw -
1. Put a multimeter probe between negative post and negative battery cable (which means disconnect ground cable from battery).
2. Put multimeter on DC Amps, mA. Depending on multimeter you'll want 20-100mA
3. Turn key off, turn accessories off (as if you were going to bed for example).
4. Read multimeter. If you have more than say 20-50mA on screen, go into cab and remove one fuse at a time. When/if mA drops or essentially zeros out, you've found your circuit.
5. Read factory wiring diagram for that circuit and look at each assembly and wiring harness for flaws. If nothing visible, start disconnecting items such as bulbs, computers, etc until draw disappears.