Mine wasn't there. My Haynes manual shows it. Also, the tensioner pully is adjusted with a 3/8's socket wrench with NO sockets on it. Just insert the socket wrench into the square hole and turn.
You need to fix your Vehicle Specs in your profile. It says:
Truck Specs:1995 ford ranger 2cyl
& 1995 ford ranger 6 cyl 3.0
I assume you're talking about the 3.0, so here's it's diagram along with the other v6 just in case.