Won’t turn over:/

[Lysadawnmarie]

I got an 86 GL that’s acting like the battery is dead but the battery is reading 13.5 volts. Not sure what the deal is. Terminals are clean. Won’t take a jump. Randomly turned over and started the other day but now it’s dead again. There’s no safety on the clutch.
it’s gotta be electrical, windshield wipers were coming on by themselves shortly before this happened and blinkers have been acting funny. (By funny I mean only working intermittently.)
Anyone have any idea on what the issue could be? Anything easy I could try before taking it to a mechanic?

Thanks!