Won't hold charge overnight!?
So I come out to my truck I have not started it in about 3 days and it won't start I replaced the water pump the alternator and put in a new battery now my truck runs great but only for a day it it doesn't hold the charge overnight I've had to jump it every morning any solutions?
Use a DMM's (Digital Multimeter) Voltmeter function to test if the battery is being charged at the correct rate.
Start the engine and connect the meter across the battery terminals. You should measure between 13.8V -14.2V DC to keep the battery correctly charged.
if it is not between these values check the alternator (or more correctly the regulator) which is in the alternator. If it is a "new" alternator take it back to where you got it from.
Be careful as the engine is running.
Otherwise, take it to Sears or Autozone after a jump, and they can check your alternator for you for free.
S W さんによる