• In late 1977, shorter bolts were used to mount the headlight bracket to allow it to be installed or removed with the handlebars clamped in place. The shorter bolt also allows for the mounting of the headlight bracket after mounting the speedometer / tachometer bracket underneath the handlebar upper clamp which provides easy access to the wiring connections at the headlight terminal block.
• The shorter bolts 5/16“x18 1-1/8” (43868-72) replaced the longer 5/16“x18 1-1/4” bolts (2871W). The longer bolts can also be shortened for this application. ¹⁾

• All motorcycles shipped after Jan 1, 1969 are equipped with a stoplight switch on the front brake control lever to conform with Federal Motor Vehicle Safety standards. ²⁾

• The MoCo issued a Service Bulletin on November, 28 1969 stating that the 1970 type Sportster rear brake light switch was now being supplied with mounting hardware as a kit, with wiring, (72004-67) for replacement of earlier switches used back to 1967.
  • The new switch was mounted on the (rear fork) right side and activated by an adjustable bracket on the brake operating rod.
  • The switch is also recommended for replacement on Late 1969 models (mounted at the rear chain guard). In some cases, the L69 switches strike the saddlebag when the rear fork bottoms out. The new switch solves that problem. ⁹⁾

(1973-85 Simple Turn Signal Function)
These model years HD implemented a basic turn signal circuit using a bi-metallic, current/heat-controlled, Turn Signal Flasher Unit similar to those in automobiles. The 12v power wire feeds thru the Flasher and then goes to the handlebar switches. The Left or Right handlebar turn signal switch could be pressed to feed the power to the bulbs on that side of the bike. When connected to the bulbs, thus completing the circuit, the Flasher unit would supply power until the current flowing through it would heat the bi-metallic elements sufficiently to cause a break (like a circuit breaker) in the circuit. Once the flasher cooled down, the bi-metallic elements would again conduct power to the turn signal bulbs, thus causing an on-off cycle that repeated until the handlebar switch was released.

From 1973-1981, the handlebar TS switches were small pushbuttons. They were momentary contact. The turn signal only stayed flashing while the button was depressed.
From 1982-1985, the handlebar TS housings were changed, creating a larger TS button. The switches were still momentary contact, working only while the button was depressed.

• (Converting to LEDs) - Because of the way these bikes were wired, you can replace the single current/heat-activated flasher with a new electronic flasher that is capable of properly flashing LEDs or Incandescent bulbs. However, the indicator light may need to be modified by grounding one side and feeding power from the right and left circuits thru diodes to the power side of the indicator.

From a bulletin in 1961:
Different flasher modules have different characteristics. It is important to use the appropriate one when replacing them. For instance:

• Flasher (68543-61) was originally used for directional signals with 21 candlepower to the front and rear lamps (6872-50) and 1 candlepower pilot lamps (71090-47). If any of the signal bulbs burn out, the pilot lamp in the same circuit will remain on.²³⁾ Flasher (68543-61A) was the replacement for directional signals. ²⁴⁾
• Flasher (68542-61) is used for pursuit lamps or other flashing lamps which use either one or two 32 candlepower lamps (68715-49).²⁵⁾