I'll check that connection after work. I own an analog multimeter, but don't know how to use it yet. I reckon I can get a digital one.
Load tester I can get.
12v charger I can get. Help an ignorant man....why a 12v charger? Just charge one batt? That will be enough to crank? Or charge one at a time?
Before working on any electrical problem, you should always verify the condition of the batteries. Fully charged and load tested. Just because it has the correct voltage it may not work when put under a load. I have seen toooooo many bad batteries.
12v charger because the batteries are 12v. Charge one at a time.
Your analog meter is fine but a digital can give you better and more acurate readings.
Help yourself and learn how to use the voltmeter.
With the trucks being 25+ years old, finding someone to work on them is getting harder and more expensive. Everyone wants to work on the new cars and make a bunch of money doing it.
You can learn your vehicle and save a bunch of money. They are supper simple. Just takes some studying and learning.