Originally Posted by cryptic3
Was that necessary?
No, but a meter is if you want to save yourself some cash while owning a ZJ. It wasn't a personal attack, just an attempt at sarcastic humor.
Honestly, If you have the smarts to be a computer / IT / software type, you have the ability to use a meter and inerpret the results. Without one you are just guessing and, in most cases, so is everyone else who may offer advise. You can pick a cheap one up for around 15-20 bucks. You can get that back by ruling out one sensor you would have otherwise changed. They are good to have for other household stuff too.
There are some things you can do without them, like give everything a good cleaning and inspection, and you need a basic set of tools for that.
There are some good youtube videos that give instructions on basic troubleshooting of charging systems and most of them involve using a meter. So does the link I provided earlier.
You might get lucky and replace the battery and all will be well. If not it will take some troubleshooting to figure out what's really wrong with it.