The source guide lists 2019–2024 Mercedes-Benz A-Class 177 and CLA118. Its product and wiring illustrations identify W177. Before using the illustrated connections on a CLA118, confirm the exact vehicle, kit, harness and module version with the kit supplier; the photographs alone do not establish an identical CLA118 installation.
The source describes three configurations: integration with factory ambient lighting, integration with retrofitted ambient lighting, and standalone installation. Standalone installation requires vehicle programming. The required programming procedure is not included here.
1. Kit components
The numbered parts in the product illustration are:
- Multicolor light strips for all four doors.
- Harnesses connecting the front-door light strips to the modules.
- Rear-door light-strip terminal leads on the door side.
- Active ambient-light modules.
- Module power-adapter harnesses.
- In-vehicle terminal harnesses linking the rear-door light strips to the front-door wiring.
The product illustration is labeled for the 2019–2024 A-Class W177. The text above clarifies its numbered parts.
2. Wiring overview
The overview shows a front-door light strip and an active module on each side, with terminal connections continuing to the corresponding rear-door strip. Later photographs also show a module labeled for the rear door, and the DIP-switch table has separate front- and rear-door settings. The overview does not explain how those module positions and configurations relate. Confirm the complete wiring layout for the supplied kit before connecting it.
This overview does not provide connector cavity numbers or a complete electrical pinout.
3. Installation overview
Before fitting the strips, the source calls for connecting the modules and checking that the strips illuminate normally. Use the verified connection procedure for the supplied kit for this test; this guide does not specify a test power supply or electrical ratings.
For integration with factory or retrofitted ambient lighting, the source says to remove the light units from the front-door ambient-light trim. It also permits trimming the front- and rear-door strips and calls for a small opening in the rear-door panel without damaging its surface covering. Cut positions, permitted cut length, hole dimensions and drilling clearance are not specified. Obtain those details before cutting or drilling.
The photographs below document the source vehicle. Confirm the vehicle-specific trim, electrical and B-pillar/seat-belt procedures before disassembly. Fastener tightening values and the vehicle power-isolation procedure are not supplied.
Front doors
The front-door photograph sequence shows:
- The light-strip position along the dashed line on the door trim.
- Removal of two door-panel screws using a T30 tool. T30 describes the tool, not the door panel.
- Release of the door-panel retaining clips and a horizontal outward pull.
- Release of the large outer locating clip.
- Release of the interior door-handle cable from its retaining holder.
- Disconnection of the factory door-module and door wiring connectors.
- Connection of the adapter to the factory door module's white connector identified as No. 3 in the photograph.
- Connection of the front-door module harness.
No. 3 identifies the connector in the source photograph; it is not an instruction to use terminal cavity 3. Verify the connector and harness match before connecting them.
Read the T30 tool and white No. 3 connector references as clarified above.
Rear doors
The rear-door photograph sequence shows:
- The strip position along the dashed line on the rear-door trim.
- Removal of two door-panel screws using a T30 tool.
- Release of the retaining clips and a horizontal outward pull.
- Release of the interior door-handle cable from its holder.
- Disconnection of the factory door module's blue connector identified as No. 6.
- A dashed wiring route with labels for the B-pillar door-to-body terminal lead and the rear-door module.
- Removal of the sill trim between the A- and B-pillars.
- Routing of the rear-door module power lead through the door wiring boot.
- Connection of the module labeled for the W177 rear door.
No. 6 identifies the blue connector in the source photograph, not terminal cavity 6. The photograph does not establish the connection for another module or vehicle version.
The source photographs include a rear-door module. Confirm its role and location against the wiring instructions for the supplied kit.
Door-to-body wiring and panel opening
Do not choose an unused connector cavity from these photographs. The source says to insert female and male terminals into empty positions but gives no cavity numbers, circuit identification or matching terminal map. Obtain the exact connector and cavity pair, terminal-locking instructions and B-pillar/seat-belt trim procedure before carrying out this part of the installation.
The ten photographs show the following operations and locations:
- Front-door wiring routed along the existing factory wiring.
- The B-pillar door-to-body connector, circled beside the rear-door opening. This is not a sill connector.
- Removal of the upper B-pillar trim.
- Release of the B-pillar door-to-body connector.
- Withdrawal of the connector's inner insert.
- Sideways removal of the female-terminal carrier.
- Addition of a female terminal to an empty cavity; the source does not identify the cavity.
- Sideways removal of the male-terminal insert.
- Addition of a male terminal lead to an empty cavity; the matching cavity is not identified.
- A small opening made below the door trim for the light strip; its dimensions and clearance are not provided.
These photographs show the general process. They are insufficient to select terminal cavities or determine drilling dimensions.
4. Functions shown in the source
The function illustration describes four controls:
- Single-color wheel: selects a single color for the active light strips.
- Color combinations: selects a multicolor setting for the active light strips.
- Welcome function: when enabled, the source describes a flowing-light effect on unlocking after the vehicle has fully entered its sleep state.
- Climate function: when enabled, temperature adjustments trigger the flowing-light effect described in the illustration.
Confirm the functions available in the vehicle's ambient-light configuration after any required programming. The illustrated menu labels may differ from those on the vehicle.
The illustration shows the source vehicle's function examples.
5. Troubleshooting
- Light strips do not illuminate. For integration with a retrofitted ambient-light system, first check whether that system operates normally. For standalone installation in a vehicle without ambient lighting, check that the required programming has been completed and that the correct single module has the standalone response setting. The source does not identify which module to change; confirm it before altering the switches.
- Factory door functions are abnormal. Check whether any connector or part was omitted during reassembly. The source also suggests checking whether the symptom clears with the module power-adapter harness disconnected and checking the DIP-switch settings. Follow the applicable electrical procedure before disconnecting a harness.
- Ambient-light functions are abnormal. If the product is connected to retrofitted ambient lighting, check that the existing retrofit module operates normally.
- A front seat belt behaves abnormally. The source directs attention to incomplete B-pillar trim reassembly. Stop and have the trim and seat-belt operation checked using the vehicle's service procedure; a lighting check alone does not establish correct restraint-system operation.
6. Module DIP-switch reference
The source says the factory default is a non-response configuration. For standalone active-light installation, it says to change one module to the response configuration. It does not identify that module or specify the applicable module hardware/software version. Confirm both before applying the table.
The source table reads:
| Source configuration | Switch 1 | Switch 2 | Switch 3 | Switch 4 | Source note |
|---|---|---|---|---|---|
| Front doors | ON | ON | OFF | ON | Integration with factory or retrofitted ambient lighting |
| Rear doors | ON | ON | ON | OFF | Integration with factory or retrofitted ambient lighting |
| Response | ON | OFF | OFF | ON | Standalone active ambient lighting |
Read switch numbers and the ON marking on the actual module. The table does not replace the missing standalone programming instructions or resolve the module layout described above.
The four-switch settings above reproduce the source table without assigning an unverified module or connector pin.