Are you in a standard tranny or automatic?

Sounds like an autobox, but not certain.

What you named the "downshift arrow" on an autobox car is an amber upshift arrow. When on it indicates that the overdrive is inhibited from engaging. That would mean no "fourth" gear.

If it is the o/d relay, try this: While driving when the car should be in o/d, give a medium whack to the dash at the point where the glove box door meets the coin tray right end. The relay is behind there, and may jar into tripping.

Good Luck,

Bob

;>)

Please clarify.