i just got a 89GTA 5.7 tpi and the cruise doesnt work. i have another 89TA in the driveway and the cruise worked on it b4 it got totalled. so i swapped the vacume servo thing next to the washer resevoir. and it didnt help. what other components r there in the cruise control? because i got all the spare parts. i dowt it is the switch. but i could swapp the whole collum out. if i knew where the control module out i can swap it out too sorry so long thanks for the info.

 

The cruise is powered from the 10 amp gauges fuse. You may want to check the brake pedal switch (gray wire & brown wire (auto trans) or gray/wht wire (manual trans)), as it disengages the cruise control if the switch is open (brake padal depressed. Also, if you have a manual trans, there is a switch on the clutch (brown wire & gray/wht wire), too. It opens when the clutch pedal is depressed & disengages the cruise, too. There should be 12 volts at the brown wire with the cruise & the ign switches on & the voltage should go away if the brake or clutch are depressed.

Also, check the vacuum release switch at the brake pedal. If it is leaking, the cruise will not work - try removing the large hose at the cruise servo, under the hood, & cap off the large pipe on the servo.

The cruise control module is under the passenger side kick panel (the ECM is toward the right & the cruise module is toward the left). It is a black box, about 4" x 5" x 1", with one multiwire connector attached to it.

Tim

 

if you have a leak in one of your vaccum hoses it could be the problem too - just a thought

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91 z28 lb9 5 speed - hooker 1 5/8 headers - high flow cat 3 inch exhaust - home made ram air - tpis airfoil - dual chamber flowmaster - car used to be fast - lt1 auto killer - had a stock re-build on the lb9 - and now it sucks a$$

 

Good point - verify that there is vacuum at the small hose going to the servo.

Tim

 

that was the very first thing i checked and all the vacume lines have great vacume. i really think it is electrical because i cant pin point the 12v
(please read other post on the topic)
thank you ed