Cruise control

[ngodline12]

hi,
i have a 1982 chev silverado 4x4, 6.2 of course. it has a cruise control. i have no idea if it works or not and i have the truck in the barn getting some badly needed TLC before i put it back on the road.
does any one know where i can find any kind of schematic or diagram for the cruise control? i did a brief search on the web but didn't see anything obvious.
thanks
mike

[hatzie55]

hi,
i have a 1982 chev silverado 4x4, 6.2 of course. it has a cruise control. i have no idea if it works or not and i have the truck in the barn getting some badly needed TLC before i put it back on the road.
does any one know where i can find any kind of schematic or diagram for the cruise control? i did a brief search on the web but didn't see anything obvious.
thanks
mike
I have 73-80, 83, & 85-91 GM CKRV wiring manuals. I also have CruseMaster, CruseMaster II, & Cruise III training manuals.

82 is a transition year. It could have Mechanical CruiseMaster, CruiseMaster II (with Resume) or Electronic Cruise III.

Both of the CruiseMaster systems are VERY simple to troubleshoot and repair. The most common failure points are the brake/clutch switches and the turn-signal stalk switch. The transducer is a mechanical governor similar to a steam engine governor that varies vacuum to the throttle servo.

CruiseMaster will have a transducer with one electrical connection on the inner fender in the middle of the speedometer cable and a single button activation switch on the turn-signal switch.

CruiseMaster II will have 2 electrical connections on the transducer and a resume switch on the turn-signal stalk.

Cruise III is vacuum with embryonic electronics. It has no chunky mechanical transducer on the inner fender there's an optical pickup on the back of the speedometer cluster. The servo has a vacuum connection and a square electric plug.

[flomulgator]

Does the optical pickup look like a really big vacuum tube? Becuase I'm pretty sure I have the Cruise III you described and I have a big tube that goes from the unit to the back of the instrument cluster.

I'm trying to diagnose why mine is failing. It just can't hold cruise for long and then once it goes it is pretty much gone for the rest of the trip odd that it kind of works once per trip. An ideas? Common modes of failure for the Cruise III?
Ride is a 1991 GMC Suburban with 6.2