Nope, low fuel lights came in 86 & up. You can swap an 86 & up sending unit in to the 85 tank but the connector is different, it has an extra wire for the light.
Really? I have a Fuel Light in my instrument panel that's never worked. ('83 mini) I always assumed it was for a low fuel light but was broken. (Now this fuel light has never lit, and I can only barely make out the outline when the sun hits the dash panel juuuust right..) Now I'm curious if their is actually a fuel light there or if I'm crazy.