How to Replace Light Bulbs on a 2026 Harley-Davidson Nightster (RH975 — Revolution Max 975T)

Harley-Davidson Nightster RH975 · 2026 · Light Bulbs

Light Bulb Replacement Guide: 2026 Harley-Davidson Nightster RH975

This guide covers every exterior light bulb position on the 2026 Harley-Davidson Nightster (RH975), which uses the Revolution Max 975T engine. The Nightster is a Sportster-family model but features more modern LED lighting than its predecessors.

Quick Reference Bulb Table

Difficulty & Time Estimate

• Difficulty Level: Beginner (1 out of 5)
• Estimated Time: 20-40 minutes (headlight is sealed LED — no bulb swap needed)
• Best Done: In a well-lit area with the bike on a level surface

Complete Tool List

OEM Part Numbers & Aftermarket Alternatives

Step-by-Step Replacement Instructions

Step 1 — Safety First

1. Park on a level surface; engage the ignition off.
2. Turn the ignition switch to OFF and remove the key fob.
3. Allow the motorcycle and engine to cool completely before beginning work.
4. Wear nitrile gloves to prevent skin oils from contaminating halogen bulb glass.

Step 2 — Headlight

The Nightster uses a sealed LED headlight from the factory. There is no individual bulb to replace — the entire sealed optical unit must be replaced if the LED fails.

If complete LED headlight replacement is needed: 1. Turn the handlebars fully to access the headlight mounting hardware. 2. Remove the two T-25 Torx bolts securing the headlight to the fork triple clamp bracket. 3. Disconnect the main wiring connector behind the headlight by pressing the locking tab. 4. Remove the old headlight assembly. 5. Position the new 5.75" LED headlight unit in the bracket. 6. Reconnect the wiring harness. 7. Install and hand-tighten the T-25 Torx bolts. 8. Torque bolts to 60-96 in-lbs. Do not overtighten.

Note: If your Nightster has aftermarket headlight modifications, the sealed LED may have been replaced with a removable-bulb unit. In that case, follow the procedure for your specific aftermarket headlight.

Step 3 — Front Turn Signal Bulbs (1157NA — Amber)

The front turn signals are mounted in the fork leg assemblies.

1. Turn the handlebars to access the turn signal you want to replace.
2. Gently pry off the amber lens cover using a flathead screwdriver wrapped in cloth.
3. Push the bulb in slightly and twist counter-clockwise to release from the socket.
4. Pull the old bulb straight out.
5. Insert the new 1157NA amber bulb into the socket and twist clockwise to lock.
6. Press the lens cover back into place until it snaps.
7. Repeat on the other side.

Step 4 — Rear Turn Signal Bulbs (1157NA — Amber)

The rear turn signals are mounted at the ends of the rear fender.

1. Loosen the retaining bolt at the base of each turn signal housing.
2. Gently pull each housing away from the fender.
3. Remove the rear rubber grommet cover to access the bulb socket.
4. Push the bulb in slightly and twist counter-clockwise to release.
5. Pull the old 1157NA amber bulb out.
6. Insert the new bulb and twist clockwise to lock.
7. Reinstall the rubber grommet cover.
8. Position the housing back into the fender bracket and tighten the bolt to 60-96 in-lbs.

Step 5 — Tail / Brake Light Bulb (1157 — Dual Contact)

The Nightster features an integrated rear fender tail light assembly.

1. Look underneath the rear fender — the tail light assembly is mounted inside a reflector housing.
2. Remove the two Phillips screws from the outer edge of the tail light lens.
3. Carefully separate the lens from the housing.
4. The 1157 bulb is a push-and-twist type. Push in gently and rotate counter-clockwise.
5. Pull the old bulb out.
6. Align the two offset pins on the new 1157 bulb with the socket tabs.
7. Push in and twist clockwise to lock.
8. Reassemble the lens and housing. Torque screws to 25-35 in-lbs.

Step 6 — License Plate Light Bulb (194 / W5W / T10)

The license plate light is a small wedge bulb on the rear fender.

1. Locate the license plate light housing on the rear fender struts.
2. Remove the 5/16" bolt or Phillips screw holding the housing.
3. The 194 bulb is a wedge-type — pull it straight out of the socket.
4. Insert the new 194 bulb by pushing it straight in.
5. Reinstall the housing and tighten the bolt.

Step 7 — Front Running Light Check (1157)

The Nightster uses dual-filament 1157 bulbs that serve as both running light and turn signal. Running light uses the low-filament; turn signal uses the high. If replacing:

1. Follow the front turn signal procedure in Step 3.
2. Use a dual-filament 1157 (not 1156 single-filament).
3. After installation, verify both filaments illuminate independently.

Step 8 — Test All Lights

1. Insert the key fob; ensure the ignition is ON.
2. Verify LED headlight illuminates (do not stare directly into LED).
3. Test the left turn signal (front and rear flash in unison).
4. Test the right turn signal.
5. Press the front brake lever — verify bright brake light.
6. Squeeze the rear brake pedal — verify bright brake light.
7. With ignition ON but lights off, check the tail light for dim running glow.
8. Verify the license plate light is illuminated.

Step 9 — LED Upgrade Considerations

If upgrading to LED bulbs: 1. Headlight: The Nightster already has factory LED. Aftermarket upgrades offer different beam patterns or projector styles. 2. Turn Signal LEDs: CAN bus may interpret low-draw LEDs as burnt-out bulbs. Install Harley-Davidson load equalizer p/n 68194-04 per turn signal pair if hyper-flashing occurs. 3. LED polarity: Flip 180° if an LED does not light. 4. Error codes: The Revolution Max platform may log lighting faults in the ECM. These clear after cycling the ignition with properly-resisted LED installations.

Step 10 — Final Verification

1. Check that all lens covers are fully seated and weather sealed.
2. Confirm no tools left near the motorcycle.
3. Take a short test ride at night to verify all lighting is functional and properly aimed.

Tips & Warnings Table

Common Mistakes to Avoid

Proper Disposal

• Halogen bulbs: Dispose with regular household trash — they do not contain mercury. Wrap in paper to prevent glass breakage.
• LED headlight assemblies: Take to electronics recycling or Harley-Davidson dealer — LED units contain driver circuitry.
• Used bulbs: Take to auto parts store — many accept them for recycling.

Verification Checklist

• [ ] Headlight LED illuminates (sealed unit)
• [ ] Front left turn signal flashes amber
• [ ] Front right turn signal flashes amber
• [ ] Rear left turn signal flashes amber
• [ ] Rear right turn signal flashes amber
• [ ] Tail light illuminates (running)
• [ ] Brake light illuminates (front lever)
• [ ] Brake light illuminates (rear pedal)
• [ ] License plate light is on
• [ ] All lens covers seated and sealed
• [ ] Fasteners torqued to spec
• [ ] No tools left on or near motorcycle
• [ ] ECM fault codes cleared (if applicable)

Guide created for the Harley-Davidson Nightster RH975 with Revolution Max 975T engine. Always refer to the official Harley-Davidson Service Manual for the latest specifications.