(The photo is from Bing Images. It does show a 1999 Alero, but mine is bronze in color rather than red.)
Step 1: The Steering Wheel With Controls
The switches on both the left and right side of the steering wheel are parts of one harness and are not sold separately. Internet prices for this switch harness combination come to about $53 (plus shipping and handling). Having these switches replaced at a dealership shop cost about $200 around 2007. The rest of my car still works well, but I do not want to spend that much money on a Cruise Control switch set for a twelve year old car with more than 100,000 miles on the odometer. And, should we replace the car, it will be easier to sell if the Cruise Control switch works properly.
I live in the USA and our automobiles have the steering wheel on the left-hand side of the car. When I use the phrase "driver's side" it means left side of the car. If I use the phrase "passenger side" it means the right side of the car. I realize that is not the scheme used in some other parts of the world.
Step 2: What Some Do
Step 3: Help From a Manual
Notice also the list of models covered by this manual. I bought this manual in the summer of 2000. There is a strong probability the same manual would cover most of these cars another couple of years into the future, perhaps all of them for even longer.
It might seem impractical to do an Instructable on a problem pertaining to a 12 year old car, but there are still many, many of these cars in use.
Step 4: The Fuse Panel
Second photo--The 2nd photo shows the air bag fuse's location with the fuse removed. It also shows the yellow air bag connector and red-orange safety lock. Remove the safety lock and depress the lock on the connector. Wiggle and pull to begin separating the two parts of the yellow plastic connector. The larger part of the yellow connector is loosely fastened to the car. The short front part of the connector pulls out of the longer part of the connector.
Third photo--The two sections of the yellow connector have been separated.
Step 5: Loosen and Remove the Column's Cowl
See the third photo. The top half of the column cowl has been removed. There are two recessed T-27 TORX screws on the side of the steering wheel away from the driver (toward the front of the car). Access space is limited. The space between the steering wheel and the instrument cluster is too short to allow a T-27 screwdriver. I attached a TORX bit to a 1/4 inch socket drive and a short extension. But, I also needed to turn the steering wheel so each screw hole is positioned more advantageously. I placed a hydraulic floor jack under the frame of the car at the front and raised it enough to make turning the steering wheel much easier. Turn the steering wheel so the hole is at about the 11 o'clock position for one screw and at about the 1 o'clock position for the other.
Note: When it is time for reassembly, use tape to secure the T-27 TORX screws to the socket drive. If you do not do this, the screw can drop off of the driver and fall into the inside of the steering wheel. Sometimes these screws become stuck behind the wiring harnesses and air bag mounting brackets inside the steering wheel hub. Also, after the steering column cowl has snapped together it needs to snap into just the right position in order for the three holes in the bottom cowl to align with the tapped holes in metal above the bottom cowl. This was probably the most tedious part of the whole project.
Step 6: Pull the Air Bag Assembly Away
Second photo--My manual advises to carry the air bag assembly away for storage and place it on its back so the front side is upward. Because I could not make the wiring harness release, I chose to place the air bag assembly on top of the steering wheel column in front of the speedometer. This will simply have to be sufficient.
See the yellow text boxes for the location of the two mounting screws holding the On/Off switch in place. Its wiring harness simply pulls out of the side of the switch. I removed the switch in order to learn more about its cause for failure and to explore making it work again, which I was able to do. See steps 8 through 11 when you are ready.
Step 7: The Easy Fix
Tape all connections and assemble all of the parts removed. See the note on reassembly at step 5. Put the connector and the fuses back in place. Pump some hot glue under the original switch. Someone will surely push on it one day. You do not want to risk that it would somehow lock itself in the "on" position.
The second graphic shows a schematic for the shunt switch. Note the yellow text boxes for further explanation.
My manual advises keeping one's head and face out of the path of both airbags when starting the engine for the first time, just in case an air bag would activate. Wear ear protection, too. (When I finished this project I followed this advice, but there was no problem. The airbags did not deploy.)
But, if you wish to know what failed in the switch and contemplate refurbishing the broken switch so it works again, read the rest of the steps in this Instructable.
Step 8: Taking the Switch Case Apart
See the yellow text boxes for how to pry the switch assembly apart.
Step 9: How the Switch Works
Notice the tiny three-arm paw in the foreground. That is what holds this switch in the "on" position. Notice the white center. It is actually clear and it is an axle that has broken off of the clear plastic block surrounding the white "T"-shaped piece in the very center of the switch assembly. See the yellow text boxes. This little axle is slightly less than 1mm in diameter. Plastic tends to become brittle with age, and it was only 1mm in diameter from the start. That little broken axle is the reason these switches fail.
I deiced to drill into the center of what is left of the axle and glue a new metal axle in the hole. The next step describes how to get the clear plastic block out of the switch assembly so the necessary work can be done to it.
Second photo--This view shows a close-up view of the white "T"-shaped piece encased in clear plastic from which the 1mm axle broke. It gives a clear picture of the two catch teeth for the three-arm paw wheel. See the yellow text boxes.
Third photo--The circuit board lifts away from the rest of the switch frame. This photo shows the soft rubber layer separated from the circuit board. The two outer wiring harness pins switch the circuit "on" and "off." Even in this photo you can follow the circuit traces for the switch. See the yellow text boxes, too. Additional circuit traces are on the other side of the circuit board. Circuit traces beyond those from the outside switch pins relate only to the LED on/off indicator. Note: My manual has a detailed circuit diagram for the Cruise Control system, including the failed On/Off switch. While the circuit board clearly shows one simple on/off contact, the manual's diagram shows three sets of two contacts that make or break in synchronized pairs.
Step 10: Restore the Old Switch
First photo--Pinch the two black tabs together and slide the clear plastic block upward and off of the switch frame.
Second photo--I used a wire brad mounted in a hobbyists chuck for very small drill bits. I had to remove the head from the wire brad to fit it into the hobbyists chuck. I used the pointed end as the bit to do the cutting for the hole. Then I used the rear with a more blunt sharpened end (as a result of cutting the wire brad with a side cutter plier) to square off the hole.
Third photo--I cut the brad to its approximate finished length and glued it into the hole with epoxy glue. (The brad is shown here before it was cut and ground or filed to size.) There should be no burrs on the end of the axle. When all is ready, insert the clear plastic block back into the switch assembly.
Fourth photo--The fourth photo shows the three-arm paw installed on the new axle. Note the orientation of the notched ends of the paw arms. The paw will work only one way. Fortunately, you can test it to see if the paw rotates as the switch is activated. If the paw does not rotate, remove it, turn it over, and put it back onto the axle. Slide the switch assembly cover on and snap it back into place. There is a flat surface inside the assembly cover that keeps the three-arm paw on its axle. The length of the axle needs to be long enough, but not too long. It should not scrape on the flat area that keeps the paw on the axle.
Step 11: Check and Assemble
As in step 7 (if you chose the easy fix), assemble everything you took apart. See also the note on assembly problems and precautions in step 5. Join the yellow connector halves from step 4 and apply the safety lock. Put the 10 amp. fuse back in place. Wear ear protection. Keep your head and body away from the air bags when you turn the key and start the car, just in case one chooses to deploy.
My Cruise Control works again without spending $53 or more for a new set of switches and also without spending $200 or more to have them replaced at a dealership garage. I feel a certain sense of accomplishment at having worked out a fix and having done the job without taking the easy way out mentioned in step 7. But, that is still an option and would cost around $3 plus the time to take everything apart again if the paw breaks or if I have some other problem.