Changing Directional Signal Switch—First Generation
| 30 November 2004
Electrical gremlins that affect turn signals, emergency flashers (on cars that have them), and/or brake lights are often traceable to a bad directional signal switch; all of those circuits pass through the switch.
If your first generation Mustang has the original directional signal switch or even an old service part, you’ll probably need to replace it sooner or later; new switches are readily available from most of the Mustang parts houses. With a little time and patience, it’s a job you can do in your driveway or garage. The only special tools you’ll need are a steering wheel puller and possibly a flat blade jewelers screw driver.
This is a pet procedure of mine because there’s a myth that I want to dispel. I’ve heard and read off and on for years that to replace the switch you need to cut the wires from the old switch where they exit the steering column underneath the dash. When the new switch is in place, you need to solder the new wires to the old cutoff wires one by one making sure to match the color codes as you go. Then you need to individually tape each solder joint to insulate it from its neighbors. I expect the cut and solder routine is based on the fact that the connector block where the turn signal wires terminate is too big to pass through the channel in the steering column. But it ignores the fact that it’s quite easy to remove the wires from the block. Cutting, soldering, and taping will work but it’s a messy arduous task and completely unnecessary.
The procedure that follows came from the 1967 Ford service manual. Other first generation cars may need to adjust the procedure. Note that Ford makes no reference to soldering:
TURN INDICATOR SWITCH AND WIRE ASSEMBLY
REMOVAL
The emergency warning flasher switch and the turn signal flasher switch are integral parts of the same switch assembly.
1. Disconnect the battery ground cable from the battery.
2. Remove the steering wheel hub.
3. Remove the horn button.
4. Remove the steering wheel retaining nut.
5. Using a steering wheel puller, remove the steering wheel. Use a felt-tip marker to index the steering wheel to the shaft before sliding the wheel off the shaft.
6. Remove the turn signal switch lever. Remove the emergency flasher control knob. (Disconnect the set-speed switch wiring connector, if so equipped).
7. Remove two steering column upper collar retaining screws and remove the upper collar.
8. Disconnect the turn signal switch wiring multiple connector (near bottom of the steering column). It may be necessary to lower the hand brake control and left air vent control on some models to provide access to the turn signal wiring connector.
9. Remove the wires and terminals from the connector blocks. This can be done by depressing the tab on the wire terminal with an awl or with an empty ball point pen refill cartridge. Then, pull the wire and terminal from the connector block. Record the color code and location of each wire before removing it from the connector block. Tape the wires together and attach a piece of heavy cord to the wires to help pull the wires through the steering column during installation.
10. Remove the plastic cover from over the wires.
11. Push the lower steering column collar down. Remove the wiring retaining clip.
12. Remove the two screws retaining the switch in the steering column and pull the switch and wiring assembly out of the column.
INSTALLATION
1. Tape the wiring of the replacement switch assembly together and transfer the pull cord used during removal.
2. Pull the wires down through the steering column with the cord, and position the switch to the steering column hub.
3. Install the two screws retaining the switch assembly to the steering column hub.
4. Install the wiring retaining clip on the steering column.
5. Install the plastic cover over the wires.
6. Press the switch wires into the connector block in their correct location recorded during removal (make sure the terminal tab locks into place). Plug the connector block together with the mating connector.
7. Pull the lower steering column collar up and snap it in position.
8. Position the upper column collar and install the two retaining screws.
9. Install the emergency flasher retainer and knob.
10. Install the turn signal lever.
11. Position the steering wheel on the steering shaft and install the steering wheel retaining nut.
12. Install the horn button with its springs and the three retaining screws.
13. Install the hub.
14. Connect the battery ground cable to the battery.
15. Check the operation of the turn signals, emergency flashers, and horns.
EDITORIAL COMMENTS
1. Step nine (9) in the removal procedure says to take the wires out of the connector block and map their location by color code. You’re being told to do this while working up under the dash where it’s hard to reach and hard to see. It’s important to do it that way if all you’re going to do is R&R the same switch. But if the switch is going to be replaced, cut the entire group of wires about 2-inches above the connector block on the side toward the switch. Don’t cut the wires on the side toward the firewall or you’ll have to individually solder them back together. After cutting the wires, disconnect the block from its mate and take it out of the car so you can disassemble it on the work bench. Remove each 2-inch piece of wire and map the colors as you go. To release each wire terminal from the block, you can use an awl, an empty ball point pen cartridge, or a flat blade jeweler’s screwdriver to depress the locking tabs.
The last sentence in this step says to tape the wires together and to fasten a piece of cord to the package before you pull the wires up through the steering column. Don’t forget the cord. It’s your life line for threading the new set of wires down through the steering column during installation.
2. Removal-step ten (10) talks about a plastic cover. Not all models have the cover. Also see installation step five (5).
Removal-step eleven (11) refers to the lower collar and the retainer clip. This does not apply to cars with a 42” steering shaft. Also see installation steps four (4) and seven (7).