About a year ago the Mirada started having funky issues with the turn signal switch. When I pulled it pushed it upward for a right turn, it didn’t lock into place, so I had to hold in place for the duration of the turn. This was fairly bearable, but then about 6 months ago I started having issues with the left turn position in the same way. And finally I lost all electrical connectivity whatsoever through the switch and I was unable to do any signaling at all. Not only is this dangerous, but it’s also against lots of traffic laws and all that bad stuff so I decided that I had to repair it.
First, I did some testing to make sure that I was going to repair the correct part. I used some wire tracking and trial-and-error to find the three wires in the large wiring harness under the dash that handle the turn signals (interestingly, the emergency blinker is a completely different wire, and throughout this time the emergency flashers remained fully functional). The harness and the turn-signal wires is shown here:

Steering Column Wiring Harness
After proving that jumping the wires worked just fine and made my blinkers blink, I was pretty much positive that it was an issue with the wiring in the turn signal itself. You can see from this picture where the turn signal switch handle enters the steering column and thus where the electrical problems must be located:

Turn Signal Switch
But in order to access this area, I had to remove the steering wheel. Since I love collecting tools anyway, I bought a steering wheel puller from Advanced Auto. The first step is removing the center-cap / cover from the steering wheel. These are held in place by some light springs, so you can safely remove the cap with a flat-tip screwdriver or other flat tool:

Steering Wheel Center Cap
Then remove the nut from the center of the steering wheel. Make sure that the steering wheel is locked in place (the key is out of the ignition and the steering wheel has little to no room for movement by the locking mechanism built into the steering column). I had to use a breaker bar to get enough leverage to break this loose. You may want to use WD-40 or PBBlaster on this to help break it loose.
Before proceeding, be sure to take some chalk or soap-stone or similar and mark a line between the steering wheel and the center bolt. When you reattach the steering wheel, you will want to make sure all of the splines line up exactly as they are now, otherwise the wheel will be off-center.
After the nut is removed, hook up the steering wheel puller to the two threaded holes in the center of the wheel. Tighten the puller with the breaker bar or large wrench until the steering wheel comes free. This will provide you access to the blinker switch mechanism. The white plastic piece (called the blinker switch cam) is the one that I had to replace:

Mirada Turn Signal Switch

Turn Signal Cam
Squeeze the center of the swivel point on the cam and remove it (this works with a forked pinching-type connection to keep it locked in place and swiveling). You will have to cut the wires attached to the old cam. The new cam comes with wire tails on it. Connect the proper old wires to the correct tails and solder the connections. Remount the new cam with the screws where the old one was. At this point, you can test both the electrical and mechanical connections by using the blinker switch as normal. Note that you will have to turn the ignition to the “on” position to see the blinkers blink.
At this point the system was all working electrically for me, but I was still unable to make the cam latch into position when making right turns. By examining the mechanism in action while I moved the lever, I found that the top latch on the cam was not springy enough and not grabbing onto the nob when it was put in place. To tighten it up some I made a shim out of wire and inserted it into the lower end of the upper latch. At that point the device was able to latch in place.
The only difficult part about putting the entire mechanism back together was mounting the steering wheel back on the toothed axel coming out of the steering column. The clearance was so tight that I could not push the wheel back on. To help I positioned the steering wheel as best as I could and then used a large (1 1/4″) socket over the center of the hole on the steering wheel and striking the socket with a rubber hammer. A good minute of continuous pounding and it was back in position. Be sure to align the steering wheel using the marks that you made earlier or your steering wheel will be lopsided and awkward and everyone will laugh at you!