MG-TC: Installation of Direction Indicators
(W. J. Stubgen)
Enhancing the safety aspects of the TC, while maintaining the car's
original appearance, can be accomplished by modifying the wiring circuitry
to accept the Lucas Turn Signal Relay found in TDs. The following outlines
the main tasks:
1. Mount the Lucas Turn Signal Relay Box and the Turn Signal Flasher
on the firewall. Note that the relay frame must be properly grounded.
2. Mount the direction indicator switch in a suitable location.
3. Mount the direction indicator warning light on, or under, the dash.
Ensure the base is properly grounded.
4. If required, mount a second "D" lamp on the rear license plate bracket.
Additional tail lights mounted high on the fuel-tank end-panels should
be considered as an added safety-related option.
5. Remove the single filament bulb and socket assembly from each front
fender side light. These are replaced with double-contact socket assemblies
and bulbs (in step 6h below) after additional wiring is installed.
6. Run wiring as outlined in the "Direction Indicator Wiring Diagram",
· Disconnect the purple wire at the stop-light switch, then connect it
to a wire leading to relay terminal #7.
· Run a new wire from the stop-light switch to relay terminal #5.
· Connect the turn signal flasher terminals as follows:
1. (L) to relay terminal #1
2. (P) to the direction indicator light
3. (X) to the direction indicator switch
· Run the other wires (from relay terminals #4 and #8, and from the A4
terminal of the voltage regulator) to the direction indicator switch and
connect as shown.
· Route a new wire to run from relay terminal #3 to the left-hand stop/tail
lamp following the existing harness along the left chassis rail. To avoid
chafing, secure this wire at frequent intervals.
· Connect the right and left stop/tail lamps as shown
· String new wires from relay terminal #6 to the right front side light,
and from terminal #2 to the left front side light. The preferred route
is through the fender braces. Again, secure at frequent intervals to prevent
· Connect and insert the double contact assemblies into the side lights
and fit the new bulbs.
1. Lucas Turn Signal Relay (or equivalent)
2. Direction Indicator Switch (single pole double throw, with centre off)
3. Flasher (3 terminal, 12 volt)
4. Direction Indicator Warning Light
5. Double Contact Sockets (2)
6. Bulbs, double filament (2)
7. Stop/Tail Lamp (a second "D" lamp)
8. Wire (16 guage)