brakes
Brake Light Switch
for 2012 Tesla Roadster Single Motor RWD · RWD
Difficulty
Easy
Time
30 min
Tools
5
Steps
6
Replace the brake light switch on a 2012 Tesla Roadster. The Roadster is built on the Lotus Elise platform, so the switch is a Lotus-sourced component mounted on the brake pedal bracket under the dash.
Warnings
⚠️The 2012 Roadster has a high-voltage battery pack behind the seats. Do not disturb the firewall, orange cabling, or PEM (Power Electronics Module). This job is confined to the driver footwell only.
⚠Roadster service information and parts are extremely scarce. Confirm switch part compatibility before ordering — many are shared with Lotus Elise/Exige but not all.
⚠The Roadster uses a fiberglass/carbon body and aluminum chassis. Do not lever against body panels — they crack easily and are expensive/difficult to source.
ℹ️If the brake lights stay on constantly, do not drive — this can drain the 12V auxiliary battery and may also affect regen behavior on this vehicle.
Tools required
Trim panel removal tool set
Small flat-blade screwdriverEssential
Multimeter (for switch continuity verification)
Insulated gloves (for 12V disconnect)Essential
Flashlight or headlampEssential
Parts
- Brake light switch (Lotus Elise/Roadster spec) × 1 — Manufacturer-specified brake light switch — verify against VIN with Tesla Roadster parts catalog
Preparation
- Park on level ground, place in P (or in gear if manual transmission variant), engage parking brake.
- Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
- Disconnect the 12V low-voltage auxiliary battery. On the 2012 Roadster the 12V battery is located in the front trunk area — refer to the Roadster Owner's Manual for exact access.
- DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal.
- If at any point you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
- Position the driver's seat fully rearward and tilt the steering wheel up (if adjustable) for footwell access. The Roadster has an extremely cramped footwell — be patient.
- Have a flashlight ready; the brake pedal bracket is poorly lit even with the door open.
Procedure
- 1Locate the brake light switchLying on your back in the driver footwell, look up at the top of the brake pedal assembly. The brake light switch is threaded into a bracket above the brake pedal arm and contacts a tab on the pedal when the pedal is at rest. It will have a small 2-wire electrical connector attached.
- 2Disconnect the electrical connectorDepress the locking tab on the switch's electrical connector and pull it straight off. The connectors on this vehicle are over a decade old and become brittle — apply gentle, even pressure. Inspect the connector terminals for corrosion or heat damage and note for later.⚠If the connector locking tab breaks, the connector may need to be replaced or repaired — do not force it.
- 3Remove the old switchThe brake light switch on the Roadster is typically either a quarter-turn bayonet style or a threaded type with a locknut, consistent with the Lotus Elise donor platform. Identify which type is fitted: for bayonet style, depress and rotate counterclockwise approximately a quarter turn to release; for threaded style, loosen the locknut and unscrew the switch from the bracket. Note the depth/position of the original switch before removal — this sets the activation point.⚠Do not pry against the pedal box bracket with metal tools — the bracket is part of the chassis structure.
- 4Compare old and new switchesPlace the old and new switches side by side. Confirm body length, plunger length, thread pitch (if threaded), and connector style all match. If anything differs, STOP and verify part number before installing — an incorrect switch can cause permanent brake-light-on or brake-lights-never-on conditions.
- 5Install the new switchInstall the new switch into the bracket using the same method as removal. For threaded types, thread it in until the plunger just contacts the pedal arm at rest, then back off per the manufacturer's adjustment specification and tighten the locknut. For bayonet types, insert and rotate clockwise to lock. The pedal at rest should fully depress the plunger so the switch is OPEN (lights off); releasing the pedal should not allow the lights to come on, and pressing the pedal should turn lights on within the first few millimeters of travel.ℹ️There is no published Tesla torque spec for this switch. Hand-tight plus locknut snug is correct — do not use a torque wrench on a plastic switch body.
- 6Reconnect the electrical connectorPush the connector straight onto the new switch until the locking tab clicks. Give a gentle tug to confirm it is fully seated.
Reassembly
- Reconnect the 12V auxiliary battery (negative terminal last).
- Allow the vehicle's low-voltage systems to wake and self-check before testing — on the Roadster this can take 10-30 seconds after 12V reconnection.
- Return the driver's seat and steering wheel to their original positions.
Verification
- With the key in the ON position (or vehicle 'ready'), have an assistant observe the rear of the car. Press the brake pedal — both rear brake lights and the CHMSL (center high-mount stop lamp) should illuminate immediately.
- Release the pedal — all brake lights should extinguish completely. Watch for a half-second to confirm no lingering glow.
- Cycle the pedal 5-10 times and confirm consistent on/off behavior with no flicker.
- Confirm that the vehicle will shift out of P/neutral only with the brake pedal pressed (brake-shift interlock function on applicable variants).
- Confirm cruise control (if equipped) cancels when the brake pedal is tapped.
- Check the instrument cluster for any new warning lights. Clear any stored faults if you have access to Roadster diagnostic equipment.
- Note: While under the dash, this is a good opportunity to confirm brake fluid was changed within the last 2 years — Tesla's published recommendation is brake fluid replacement every 2 years regardless of mileage.