Cruise control switch won't work on a 2003 Alero

It's probably a problem with cruise control module , located under the hood in engine compartment . Or a bad connection somewhere . Do you know how to do electrical testing ? Is the air bag light lit on the instrument cluster ?

Could have DTC'S - diagnostic trouble code's stored .
DTC P1554
The powertrain control module (PCM) inhibits cruise control operation when certain conditions are not appropriate for cruise control operation. The PCM removes the ground from the cruise control inhibit signal circuit in order to disengage cruise control operation.
DTC P1585
Output driver modules (ODMs) are used by the powertrain control module (PCM) in order to turn on many of the current driven devices that are needed to control various engine and transaxle functions. DTC P1558 set indicates that an improper voltage level has been detected on the signal circuit which controls the cruise control inhibit circuit.
Action Taken When the DTC Sets
• The PCM will not illuminate the malfunction indicator lamp (MIL).
• The PCM will store the conditions present when the DTC set as Failure Records data only.

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. However, steep grades may cause variations in the selected speeds. The electronic cruise control system has the capability to CRUISE, COAST, RESUME SPEED, ACCELERATE, and TAP-UP or TAP-DOWN.
The main parts of the cruise control system are:
• The cruise control module assembly
• The function control switches
• The cruise control release switch
• The clutch pedal position switch (CPP), if equipped
• The stop lamp switch assembly
• The vehicle speed sensor
The cruise control system uses the cruise control module assembly to maintain the desired vehicle cruise speed and operation. The cruise control module assembly has an electronic controller and an electric stepper motor to vary the throttle in each different cruise control mode. The electric controller monitors vehicle speed and operates the electric stepper motor. The stepper motor operates in response to the electronic controller, to maintain the desired cruise speed. The electric stepper motor moves a strap that is attached to the cruise control cable which moves the throttle linkage. The cruise control module assembly contains a low speed limit which will prevent system engagement below a minimum speed of 40 km/h (25 mph). The module assembly is not serviceable.

try this site. Fix Cruise Control Switch Olds Alero and Others

Try checking the small switch at the top of the brake pedal. There may be two one for brake lights and one for the cruise control. To ascertain what is what, pull one wire off and see if brake lights work. If not, then the other switch controls the cruise control disconnect and engage..I you have a DC test light check to see if power is on on both side of the switch with brake pedal up. If so, depress pedal and check power on the other side there should be none, if there is the switch is defective.

check cruise control fuse and check the brake lights see if brake light working because the brake light switch will deactivate cruise control when brakes is applied.if brake lights dont work either fuse blowed or switch bad.if all is good have vechicle code scan because cruise control control by PCM and vechicle speed sensor and thottle actuator control motor.

On these case,to troubleshoot these problem,there are solved help links.Click the link directly and refer the details to solve these problem yourself,with help of diagrams:------
Ford ranger cruise control not working?

http://technoanswers.blogspot.in/2012/02/ford-ranger-cruise-control-not-working.html

----------- Horn and Cruise control quit working?

http://howtobyme.blogspot.com/2011/11/horn-and-cruise-control-quit-working.html

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Horn and cruise control not working on Plymouth Grand Voyager?

http://howtobyme.blogspot.com/2011/11/horn-and-cruise-control-not-working-on.html

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Horn and Cruise control quit working on 2003 Jaguar S-Type? http://howtobyme.blogspot.com/2011/11/horn-and-cruise-control-quit-working-on.html

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Cruise Control stops working, Excessive cranks to start the engine and RPM goes max 2500 http://whoisbyme.blogspot.in/2012/07/cruise-control-stops-workingexcessive.html

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Cruise control stop working on 1994 Ford ranger? http://technoanswers.blogspot.in/2012/02/cruise-control-stop-working-on-1994.html

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Cruise control not working? http://schematicsdiagram.blogspot.com/2011/12/cruise-control-not-working.html

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1996 Ford Explorer: Cruise Control Wiring Diagram?

http://schematicsdiagram.blogspot.in/2012/06/1996-ford-explorer-cruise-control.html
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These will help.
Thanks.

Yes, there is a fuse. Could be the vehicle speed sensor, could be a bad wheel bearing, could be cruise control switch, could be transmission control module, could be brake light switch.

{: ) Check the fuses at the I/P fuseblock labelled CRUISE(10amp) and STOP(15amp). Also check the the ETC/ECM fuse(15amp) at the underhood fuseblock. A faulty brakepedal switch is most likely the cause. The cruise control system will not function properly if this switch is giving inaccurate voltage signals.

Start with the simple and check the fuses and the Stop lamp switch. Check your brake lights, if they're not working, the cruise won't work either. If they're not working, check the fuse for them, if the fuse is fine, then take it into the dealer, there's been a recall issued on the brake switch, so it should get fixed for free.
Cruise Control Disengaged
The powertrain control module (PCM) disengages the cruise control operation based on the signals from the following switches:

* The stop lamp switch
* The TCC brake/cruise release switch
* The clutch release switch, if equipped
* The cruise control On/Off switch

The TCC brake/cruise release switch and the stop lamp switch are mounted on the brake pedal bracket. When the brake pedal is applied, the normally closed TCC brake/cruise release switch opens and the normally open stop lamp switch closes. The PCM detects a low signal voltage on the TCC brake/cruise release switch signal circuit and a high signal voltage on the stop lamp switch signal circuit. When the clutch pedal is applied, the normally closed clutch release switch opens and the PCM detects zero voltage on the CCP switch signal circuit. The vehicle speed stored in the memory of the PCM will be erased when the cruise control On/Off button is turned OFF, or the ignition switch is turned OFF.

The Cruise Control System will disengage when the PCM detects that a driver override function has been active for approximately 60 seconds .

When the Cruise Control System is disengaged, the PCM sends a class 2 message to the instrument panel cluster (IPC) in order to deactivate the cruise control indicator.

Cruise Control Inhibited
The powertrain control module (PCM) inhibits the cruise control operation when any of the following conditions exist:

* A cruise control related DTC has been set.
* The vehicle speed is less than 40.2 km/h (25 mph) .
* The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
* The engine RPM is too low.
* The engine RPM is too high, with fuel cut off.
* The vehicle speed is too high, with fuel cut off.
* The system voltage is not between 9 volts and 16 volts .
* The Traction Control System (TCS) is active for more than 2 seconds .
Thank you for using Fixya and start with replacing the stop lamp switch. Even though the brake light work, it;s been known for that switch to cause your issue. that's way there was a recall for it.

Check the switch, located on the brake pedel the stop light switch and the cruise control switch are on the brake pedel towards firewall. The cruise control switch is plastic.

use a scanner to check the abs system . most of the time the abs brakes and traction control system work together. your cruise control . unit has a servo motor .in front right fender well. check the fuse and relay also the cruise control brake release switch. and the brake light switch.if all is good you have a cruise control module problems. dealer ship job.