Introduction: Change an Ignition Switch Without Removing the Dashboard

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About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first to…

This Instructable will show how I replaced the ignition switch in my car without removing the dashboard.

In a recent Instructable I discussed problems with the instrument cluster on my 1999 Oldsmobile Alero. In that previous Instructable I had believed my ignition switch tested good and I soldered some metal-on-metal connections to by-pass oxidation that may have added a critical amount of resistance to the circuit. Still, the same difficulties returned a few days later. I read articles like this one to see if my 12 year old car with 110,000 miles could be suffering from an ignition switch in the early stages of failure. I decided I wanted to remove the ignition switch from my car for examination and possible replacement, but do it without removing the dashboard. 

The Oldsmobile Alero has some "cousins," like the Chevrolet Malibu. But, the dashboard trim in the Malibu is different from that in the Alero. In the Malibu the bezel around the radio simply pries off, and when it is removed the two bolts that hold the ignition switch in place are fully accessible. The Alero is different, though. The same two bolts are hidden behind the dashboard.

For this Instructable I needed:

A 10mm open end and box end combination wrench that I could sacrifice.
A couple of screwdrivers.
A nut driver with a 7mm wrench socket attached.
A torch for heating and bending the wrench as needed (I used a carbon arc torch on an electric welder.).
A vise (for holding the wrench while heating it for bending).
A hammer for making the bend in the wrench as sharp as possible.
A Dremel tool with a cylindrical grinding bit and a burr bit.
A mechanic's inspection mirror.
Auxiliary lighing (flashlight or a mechanic's trouble light)
A Haynes manual for my car.
A multi-meter.
A new ignition switch. 

Step 1: Ignition Switch Bezel

Before beginning it is a good idea to disconnect the negative lead from the battery to keep the air bags from deploying accidentally. If your car has an anti-theft code set for the radio, deactivate that first. 

The ignition switch bezel lifts off when pried around its perimeter with a common screwdriver. I will trim away some of the dashboard behind the ignition switch bezel and use the extra space to access the bolts.

Step 2: Working With a Dremel

I used a burr tool on my Dremel to chew away some of the plastic dashboard so that there is a chance I can get a wrench onto the two ignition switch mounting bolts. See the yellow text boxes for the location of the two bolts, each with a 10mm hex head. My plan is to remove dashboard plastic right out to the edge of the ignition switch bezel, but not so far that a gap is visible. This works because the ignition switch bezel fastens to the ignition switch and not to the dashboard.

Step 3: A Suitable Wrench

I decided to buy a 10mm combination box end and open end wrench for this project. But, I needed to modify it to work within the spatial confines presented by my dashboard. I decided to use the 12 point box end portion of the wrench, but it was too thick. So, I ground it from both sides to make it thinner. It would not fit between the inner surface of the dashboard and the top of the bolt heads before grinding. It really needs to be no thicker than the bolt head is high. I also heated the wrench to bend it in two places for a large offset. For heating prior to bending I used a carbon arc torch on a 230 volt stick welder. See additional details in the text yellow boxes.

Step 4: Fitting the Wrench Onto the Bolt Heads

In these two photos you can see how the wrench fits through the opening around the ignition switch and onto the bolt heads. After the bolts were a little bit loose, I was able to reach around through the instrument cluster opening and turn the back end of the upper bolt by hand. I could also get enough of a finger into the area around the ignition switch and push at the bolt heads to speed their removal. This also helped during installation of the new switch. I could twist the bolt between 1/12th and 1/6th of a turn before I had to reset the wrench on the bolt. This was slow, but it worked fine and I was able to get the bolts as tight as I wanted.

Before beginning I had some concerns about either of the bolts falling out of its hole when fully loosened and lodging down low behind the dashboard. I considered stuffing some newspaper behind the dashboard under the ignition switch, but that really was not necessary. Although the bolts tipped precariously, they never fully came out of their holes and they stayed in place quite well.

Step 5: Removing the Instrument Cluster

First, lower the steering column and remove the top half of the steering column cowl. Fingertip pressure is enough to separate and lift the upper cowl. (1st photo) Remove two screws from the upper part of the instrument cluster bezel. (2nd photo) Pry the instrument cluster bezel loose on opposite sides of the steering column. (3rd photo) Disconnect the wiring harness at the switch on the bezel that changes the odometer display between the trip meter and the odometer reading. Remove the instrument cluster bezel and set it aside. Remove the four mounting screws around the perimeter of the instrument cluster. Tip the instrument cluster and pull it from its nesting place. Disconnect the wiring harness. (4th photo)

With the instrument cluster removed, you can see the upper portion of the ignition switch from the lower right portion of the instrument cluster opening. 

Step 6: Access the Switch

The ignition switch can easily be accessed through the opening for the instrument cluster once the cluster and its bezel have been removed. At this point you may want to consult a repair manual for your vehicle. Some things are certain to vary. The harnesses connected to the ignition switch restrict the degree to which the switch can be moved for better access. I found a mechanic's inspection mirror and a flashlight very helpful when something would not release as I thought it should. Also, some things cannot be removed from the ignition switch until the lock cylinder has first been removed. Consult a manual before forcing something with more leverage.

My ignition switch uses an interlock cable to connect the gearshift lever to the ignition switch so the car cannot be started unless the transmission is in Park or in Neutral. The Haynes manual fails to mention that this cannot be separated from the switch until the lock cylinder has been removed. The lock cylinder is removed by inserting the key into the ignition switch and turning it to its Run position. There is also a metal retainer in a rectangle on the side of the ignition switch. Press it inward and the lock cylinder can be pulled from the switch. Also, the Passlock wiring harness (white and yellow wires) cannot be removed until the lock cylinder has been removed.  

Step 7: The Switch

The 1st photo shows the old switch viewed from the front, but with the lock cylinder removed. Notice the two arms with metal threaded sleeves to receive the mounting screws. The switch is turned counter-clockwise just a little. The lower threaded sleeve would be at 6 o'clock and the upper at 2 o'clock when in place.

See the 2nd photo for a view of the back and underside of the switch. The two wiring harnesses and the interlock cable attach here. Even though I pressed the releases on the wiring harnesses, both were very difficult to remove, especially in the confined space behind the dashboard. 

The 3rd photo shows the metal tabs in each of the two harness connectors on the switch. The diagram below is from the Haynes manual. Not all tab positions shown in the manual are filled with a metal tab. The table below tells which sets of tabs should have continuity in the various key positions. In my previous Instructable linked in the Introduction I mentioned a test at the fuse panel by which I decided the ignition switch was good. However, when I tested the switch using this table, some of the tab combinations failed the continuity test. At that moment I decided I would spend the money and buy a new ignition switch. 

The auto parts store I use is part of a chain. I was able to go onto their web page and locate the specific ignition switch my car uses and to determine my local store had one in stock. The price was also listed. These things were good to know before I had removed enough things that the car no longer starts.

Step 8: Finished

This is an actual photo of my dashboard after I replaced the ignition switch without removing the dashboard. Nothing in what you see hints that some of the dashboard has been cut away behind the ignition switch bezel with a Dremel tool. And, my car now works as it should. Although a new ignition switch is almost $100, I can avoid buying a new car for a while. I sacrificed a wrench that I may yet use again for another special job in the future, but it was well worth the extra cost of a few dollars.