How to Replace Light Bulbs on a Harley-Davidson Tri-Glide Ultra (FLHTGUT — Milwaukee-Eight Touring Trike)

Harley-Davidson Tri-Glide Ultra FLHTGUT · 2025 · Light Bulbs

Light Bulb Replacement Guide: Harley-Davidson Tri-Glide Ultra FLHTGUT

This guide covers every exterior light bulb position on the Harley-Davidson Tri-Glide Ultra (FLHTGUT), Honda's flagship three-wheel full-dress touring motorcycle. Powered by the Milwaukee-Eight 114 engine with a batwing fairing, this is the premium touring trike with the most extensive lighting suite in the Harley-Davidson lineup — including headlight, auxiliary passing lamps, fog lamps, multiple turn signals, twin tail/brake lights, rear cargo light, and accent lighting.

Quick Reference Bulb Table

Difficulty & Time Estimate

• Difficulty Level: Intermediate (2 out of 5)
• Estimated Time: 45-65 minutes (most comprehensive lighting suite)
• Best Done: In a well-lit area with the bike on an open, level surface — trike width requires extra workspace and an assistant for some rear-facing tasks

Complete Tool List

OEM Part Numbers & Aftermarket Alternatives

Step-by-Step Replacement Instructions

Step 1 — Safety First

1. Park the Tri-Glide Ultra on a level surface and turn the ignition OFF.
2. Remove the key and wait for the motorcycle to cool.
3. The Tri-Glide is the widest model in the Harley-Davidson lineup (approximately 57 inches wide) — ensure you have ample clearance on both sides for rear access. An assistant is helpful.
4. Put on nitrile gloves before handling halogen bulbs.

Step 2 — Headlight Bulb Replacement (H7)

The Tri-Glide Ultra uses a single H7 bulb housed in the iconic batwing fairing.

1. Access the rear of the headlight housing from inside the fairing — remove the inner fairing trim panel (typically 4-6 T-25 Torx screws).
2. Locate the rubber dust cover on the back of the headlight housing.
3. Pull off the rubber dust cover.
4. Disconnect the wiring harness connector (press locking tab, pull apart).
5. Release the thin wire spring clip — press down and swing out of its notch.
6. Pull the old H7 bulb straight out.
7. Do NOT touch the glass of the new H7 bulb. Use gloves.
8. Insert the new H7 bulb — the base has a specific orientation (flat edge). Align correctly.
9. Reinstall the wire spring clip — it should snap securely over the bulb base.
10. Reconnect the wiring harness connector.
11. Push the rubber dust cover back on — ensure flush contact all around.
12. Reinstall the inner fairing trim panel and all Torx screws.

Step 3 — Auxiliary Passing Lamps (H11, Both Sides)

1. The auxiliary lamps are located on each lower fairing wing, just behind the headlight.
2. Access the rear of each housing through the inner fairing cavity or from below.
3. Disconnect the wiring harness connector for each lamp.
4. Twist the socket ~1/4 turn counter-clockwise to release from the housing.
5. Pull the old H11 bulb out.
6. Insert the new H11 bulb (pins align one way only).
7. Reinstall the socket into the housing — twist clockwise to lock.
8. Reconnect the wiring.
9. Repeat on the opposite side.

Step 4 — Front Fog Lamps (H8, Both Sides)

1. The fog lamps are positioned in the lower front fairing.
2. Some Tri-Glide models require removal of a lower fairing trim piece (4-6 T-27 Torx screws) for access.
3. Disconnect the wiring harness from the fog lamp.
4. Twist the socket counter-clockwise and pull from the housing.
5. Pull the old H8 bulb from the socket.
6. Insert the new H8 bulb.
7. Reinstall the socket — twist clockwise to lock.
8. Reconnect the wiring.
9. Reinstall any removed fairing trim.
10. Repeat on the opposite side.

Step 5 — Front Turn Signal Bulbs (1157NA Amber)

1. The front turn signals are integrated into the lower edge of the batwing fairing.
2. Each has a Phillips screw (#2) on the visible face of the lens.
3. Remove the screw and gently pull the lens away from the housing.
4. Push the 1157NA bulb in and twist ~1/4 turn counter-clockwise.
5. Install the new bulb — align offset pins, push in, twist clockwise.
6. Reinstall the lens and tighten the screw snugly.

Step 6 — Rear Turn Signal Bulbs (1157NA Amber)

1. The rear turn signals are mounted on the rear fender corners of the trike chassis.
2. Remove the 5/16" or 10mm mounting bolt.
3. Gently pull the signal assembly away from the fender.
4. Disconnect the wiring connector.
5. Twist the bulb socket counter-clockwise to release.
6. Replace the 1157NA bulb (push-twist method).
7. Reinstall the socket, reconnect wiring, and re-bolt.
8. Repeat on the opposite side.

Step 7 — Tail / Brake Light Bulbs (1157 Dual Contact, Both Sides)

1. The Tri-Glide has twin tail/brake light assemblies on the rear fender.
2. Each lens is held by 2-3 Phillips screws.
3. Remove the screws and carefully pull the lens away.
4. Push the 1157 bulb in and twist counter-clockwise to release.
5. Install the new 1157 dual-contact bulb — wider offset pin first, push, twist clockwise.
6. Critical: Check the rubber gasket between the lens and housing. A damaged or displaced gasket allows moisture into the housing, causing corrosion and electrical failure.
7. Reinstall the lens and tighten screws snugly.
8. Repeat on the opposite side.

Step 8 — License Plate Light (194 Wedge)

1. The license plate light is centrally mounted on the rear chassis behind the plate.
2. Remove the housing cover Phillips screw.
3. Pull the 194 wedge bulb straight out.
4. Push the new 194 bulb straight in.
5. Reinstall the cover and tighten.

Step 9 — Rear Running / Marker Lights (194)

1. Small marker lights line the rear fender perimeter.
2. Each has a small lens held by 1-2 Phillips screws.
3. Remove the screws and gently pry the lens off.
4. Pull the old 194 wedge bulb straight out.
5. Push the new 194 bulb straight in.
6. Reinstall the lens with the rubber seal in place.

Step 10 — Rear Cargo Compartment Light (194)

1. The cargo compartment light is mounted inside the rear storage area.
2. Open the cargo lid and locate the light housing on the ceiling or wall.
3. Remove the cover (typically a twist-off or snap-off cover).
4. Pull the old 194 bulb straight out.
5. Push the new 194 bulb straight in.
6. Reinstall the cover.

Step 11 — Tour-Pak Interior Light (Festoon C10W)

1. The Tour-Pak lid has an interior light that uses a festoon-style bulb.
2. Open the Tour-Pak lid and locate the light housing inside.
3. Gently pry the lens cover off using a plastic tool or small flathead.
4. The C10W festoon bulb has metal end caps — compress it slightly to release from the spring-loaded contacts.
5. Insert the new festoon bulb — compress and slide between the two metal contacts.
6. Reinstall the lens cover.

Step 12 — Ground Effects / Accent Lights (194)

1. Ground effects and accent lights are scattered along the lower fairing and rear fender.
2. Each uses a 194 wedge bulb behind a colored or clear lens cover.
3. Remove the lens cover screws or snap the cover off.
4. Pull the old 194 bulb straight out.
5. Push the new 194 bulb straight in.
6. Reinstall the cover.

Step 13 — Final Verification

1. Turn the ignition to ON.
2. Verify headlight (low and high beam).
3. Verify auxiliary passing lamps.
4. Verify fog lamps.
5. Verify all four turn signals — steady amber flash.
6. Verify twin tail/brake lights — both sides at dim (tail) and bright (brake).
7. Test both brake inputs (lever and pedal).
8. Verify license plate illumination.
9. Verify cargo compartment light (open/close lid).
10. Verify Tour-Pak interior light (open lid).
11. Verify all running/marker lights along the rear fender.

Tips, Warnings & Common Mistakes

Old Bulb Disposal

• Halogen bulbs: Contain pressurized halogen gas — wrap in original packaging before disposal. Do not throw loose in trash.
• LED bulbs: Dispose as e-waste at electronics recycling centers.
• Festoon bulbs: Small metal/glass — wrap before disposal.
• Keep original boxes for spare bulb storage in your toolkit or saddlebag.

Verification Notes

1. Headlight aim: Park 25 feet from a flat wall. Low beam should strike 2-3 inches below center height. High beam should center with a bright hotspot. Adjust via the two vertical screws on the headlight bucket rear.
2. Twin tail light sync: Both left and right brake lights must illuminate simultaneously and at equal brightness. A difference signals a ground issue or incorrect wattage bulb.
3. Flash rate: 60-120 flashes per minute. Uneven or fast flashing on one side indicates a bad ground or wrong bulb.
4. Fog lamp coverage: Each fog lamp should create a wide, low beam pattern on the road. If one seems dim or off-axis, check bulb seating and housing alignment.
5. Weather seal verification: After completing all replacements, a gentle hose spray (never pressure washer) around all housings confirms no water intrusion. Pay special attention to the twin tail lights, fog lamps, and Tour-Pak light seals.
6. Cargo compartment light: Open the rear cargo lid — the light should illuminate. Close the lid — it should extinguish (door switch operation).

Frequently Asked Questions

Can I upgrade all Tri-Glide Ultra bulbs to LED? Yes. H7, H11, H8, 1157, 194, and festoon C10W all have LED replacements. LED headlight and passing lamp bulbs include heat sinks — verify clearance inside the batwing fairing before purchasing.

What H7 LED is recommended for the Tri-Glide Ultra? Philips X-tremeVision H7 LED or Sylvania ZEVO H7. Ensure the LED heat sink assembly fits within the batwing fairing's headlight cavity.

Does the Tri-Glide Ultra need a flasher relay update for LED turn signals? The Touring-chassis flasher module on the Tri-Glide Ultra is typically self-compensating for LED lower draw. However, if hyperflashing occurs after upgrading to LED turn signals, replace the flasher relay with an LED-compatible unit.

Can I add a backup camera to replace the Tour-Pak light housing? Aftermarket backup cameras for the Tri-Glide Ultra are available and typically utilize the Tour-Pak license plate light wiring or reverse light circuit. Consult the camera manufacturer's installation instructions.

How do I know if a rubber gasket needs replacement on the twin tail lights? Inspect each gasket carefully after removing the lens. If it is cracked, flattened, brittle, or has visible gaps, replace it. Harley-Davidson sells individual gasket kits, or you can source aftermarket equivalents from vendors like Kuryakyn or Drag Specialties.