Hey guys, so my battery keeps going dead if i dont drive it at least once or twice a day. When i drive it aorund for awhile it'll read 14 but once i park it and let it sit for over 6hrs the battery will get very low and barely turn the motor over enough to start it. The battery is brand new. Does this sound like an alternator problem like i suspect or is something drawing the charge out of it while it sits?
There are 2 thick wires going to the fuse block on the drivers side fender that goes to the 120A fuse. One goes right to the positive of the drivers side battery and the other goes to the alternator. Using a digital volt meter, check voltage on the battery terminals, should be 12.4-12.6. Then take the nut off the wire that goes from the battery positive to the 120A fuse of the fuse block and take the wire off the bolt and see if the voltage goes up any. If it does, something is drawing on the batteries. Remember that this should be done with everything off, don't have the headlights on and everything since that will be obvious when they go off that the voltage will go up.
To load test the batteries, hook that wire you took off back up. Then get the volt gauge out and put it across the battery terminals, should be in the same 12.4-12.6 range. Then turn the key on and turn the headlights on bright and the blower motor on high, do not start the truck. Hopefully the grid heaters won't be cycling (hope its warm there). The voltage should drop to maybe 12.2 volts and just kinda linger there. It's the poor mans load tester since not many people have one, otherwise go to NAPA and have them test it for you properly.
The Crank sensor is the RPM sensor that is right above the damper on the front of the engine.
did you replace bolth batterys? and do you have aftermarket sterio, cb or other acsesory? if look for obviouse first. alternators are known for doing that.easo to tell just unhook alternator wire and se if volts go up.