Is there any sort of explanation or anything that could help my situation?

What is your question?

You can jump the truck (1990 Ford Ranger) and it'll stay running, but it will not start on its own. Possibly a short around the battery? I'm honestly not too sure nor am I experienced in its mechanics all that much. Along with the back tires leaking air all day, flat by morning. I assume that's a simple fix, but again; not experienced in this field.

How long has your 1990 Ford Ranger had this problem?

1 Month