most of the time the transducer seems to be the source of the problem from what i have read. i have a 78 that someone cannibalized along the way when stuff stopped working. i will be attempting to get the cruise working in the near future. i had to get a transducer because mine was completely gone and the speedometer cable was just mated together in front of the cowl, lol. i assume you believe that the servo is ok based upon hooking it to a vacuum meter and testing it?? make certain that the switch (turn signal stalk) is sending a signal to start the system. i believe that (assuming all the fail safes are not tripped off), that the switch is what fails often also. there are several things that cause the system to shut off (stepping on the brake pedal causes a switch to break the system, there is a mercury type switch that trips if rapid deceleration is sensed, there is a fail safe that senses the drop in voltage when the brake lights come on (in addition to the switch on the brake pedal). there may be more. any one of these that is bad will cause the system to fail to go on since each indicated the system should be shut off. i'm certain there are many folks here who are a lot better versed on the system than i am, and hopefully they will add to this thread. i hope some of this will at least give you an idea of the things to start checking. hope some of it helps. steve
