Are the cruise control systems the same as other Chevys or GM models of the same year? I have an 81 and half the system was on it when I got the car. Any help would be greaty appriciated!
Thank you!
Matt

No difference. The same transducer, and although the cruise switch may look different, the function is the same. Chevrolet used the same unit for many years. They stopped when they went electronic.

There are only 3 wires to the switch, and two to the transducer. Key on supplies the switch with key on power. The other two wires are switched. The two wires go to the transducer. With the cruise switch on, one wire will have power. The other wire will have power when the SET is pushed part way. All the way cuts power off for coast down. One of these is interrupted by the brake switch. There is also two vacuum hoses to the transducer. One is engine manifuld vacuum. The other goes to the vacuum motor that pulls the link to open the throttle. This vacuum is vented by the brake vacuum switch when the brake is pushed.

If you have vacuum to the transducer, and the brake switch holds vacuum, and the vacuum motor will open the throttle, the vacuum is okay.

If you turn the key and cruise switch on, then check for power on one wire at the transducer. If you have it, contact the other wire on the transducer, and push the set button. You will see power, then it will quit. Let up on the button and you will see it light and go out again. ( it only has power in the center position) If it does this and the cruise does not work, but the speedometer works, the transducer is bad, or has lost it's ground. If the speedometer does not work, check the speedo cables and drive gear in the trans.

A few GMs had a third wire on the transducer. This turned on the cruise light on the dash.

Ken Styer

Ken,
Thank you for your info. The reason I asked is that some of the pieces I need I can't seem to find in any of the after market parts catalogs. Since they were missing since I have had the car I can't compare them to any that I find in the junk yards from other cars of the same year.
Once again thank you very much!
Matt