1989 Jeep Grand Wagoneer Vehicle Tow Bar Wiring | etrailer Fastest shipping available and a lowest price 1989 Jeep Grand Wagoneer vehicle tow bar wiring guarantee. Expert lifetime technical support on all purchases. Complete 1989 Jeep Grand Wagoneer Vehicle Tow Bar Wiring installation instructions and customer reviews. Call 800-298-8924 to place your order or order online at etrailer. 1987-1989 Jeep Grand Wagoneer Vehicle Wiring Chart and Diagram Listed below is the vehicle specific wiring diagram for your car alarm, remote starter or keyless entry installation into your 1987-1989 Jeep Grand Wagoneer information outlines the wires location, color and polarity to help you identify the proper connection spots in the vehicle.