1992 GMC Sierra

Welcome to the forum, yes, there is a wiper motor. Probably under the hood on the firewall. I'd check voltage circuits at the motor. With the key on, wiper switch on, gray wire is voltage for low speed, purple wire is voltage for high speed. Black wire is ground. If no voltage, check wiper fuse 25 amp. Also use a testlite and check fuse circuit, goes hot when you turn on the key.