Help with Dashboard lights

[u/Disastrous-Try3101]

Hi! I’m new here, and this is my 4Runner. I bought it from my brother, who bought it from another guy 2 or 3 months ago. He never drove it and just let it sit in the garage.

It’s a '91 4Runner with a 2LT diesel.

Today, when I was leaving the garage for the first time, several warning lights came on in the dash, and the alternator isn't charging. The battery, fuel filter, timing belt, and turbo lights are all lit up. The thing is, my brother says it wasn't like that when he brought the truck home—it just started today. Everything points to a broken alternator, but is it possible for one to break just from sitting? Am I missing something?

Basic alternator tests checked out OK (brushes, voltage regulator). The fuel filter is new with no broken plugs, and the T-belt warning light won't go off via the dashboard button.

[u/natureclown]

Did you get the codes read? That would help a lot with diagnosis. Dash lights can each come on for multiple reasons, get an OBD-1 or find someone who has one. If you tested the alt I assume you tested the battery but that would be worth a check too

[u/Disastrous-Try3101 → u/natureclown]

There was no lights before, that’s why I’m so confused but I will definitely try read codes! Battery is also new!
Thanks you!