Here is the 91 Bronco Cruise Diagram
"A visual inspection is an important part of the system test. When performing a visual inspection, check all components for abnormal conditions such as bare, broken or disconnected wires, damaged vacuum reserve tanks or hoses. In order for the speed control system to function properly, it is necessary that speedometer cables be properly routed and securely attached. Servo (throttle actuator) assembly and throttle linkage should operate freely and smoothly. With throttle set in high idle position bead chain should have not more than 1/8 inch freeplay. On Aerostar, Bronco II, Explorer and Ranger, actuator cable is pre-adjusted with .094 inch slack. If adjustment is necessary, cable should be adjusted as tight as possible, without opening throttle plate or increasing idle speed.
Diagnostic Test A, Speed Control Does Not Work