Tesla Model 3 tail light: 3-pin or 4-pin — which one fits?
Short answer: unplug your original tail light and count the pins on the connector. Three pins means you need a 3-pin lamp; four pins means you need a 4-pin lamp. As a rough guide, 2017–2020 Model 3 uses the 3-pin connector and 2021-onward cars use the 4-pin — but the changeover happened mid-production, so the plug on YOUR car is the only thing that's certain.
Ordering the wrong connector is the single most common mistake on Model 3 tail lights. The lamp will physically sit in the body the same way, but the plug won't mate, so the brake/turn/reverse functions won't work without an adapter harness.
What changed, and roughly when
Owners and parts catalogs report that Tesla switched the Model 3 rear-lamp connector from a 3-pin design to a 4-pin design around the 2020/2021 model years. Cars built through about 2020 typically carry the 3-pin plug; cars from about 2021 on carry the 4-pin plug.
The extra pin reflects a wiring change: on the earlier 3-pin setup the turn-signal wire also does double duty for the brake signal, while the later 4-pin setup separates those feeds. That's why a mismatched plug doesn't just "work anyway."
Why model year alone isn't enough
Because the connector changed partway through production, two cars of the same model year can have different plugs. Treat the year as a starting hint, not a guarantee — the reliable check is the physical connector on your own car.
Do this before ordering: open the trunk, pull back the trim by the tail light, unplug the lamp, and count the pins in the connector. Match that number to the lamp you buy.
Inner vs. outer lamps, and adapter harnesses
The Model 3 has four tail lights: two outer lamps on the quarter panels and two inner lamps on the trunk lid. Confirm the connector on the specific lamp you're replacing, since you may be doing one corner rather than the full set.
If you can only get a lamp in the other connector generation, adapter harnesses exist that convert a 3-pin car to a 4-pin lamp (and vice versa) so a newer OEM lamp can run on an older car. It's a supported workaround, but ordering the matching connector in the first place is cleaner.
Frequently asked
How do I know if my Model 3 has a 3-pin or 4-pin tail light?
Unplug the original tail light and count the pins in the connector. Three pins = 3-pin lamp; four pins = 4-pin lamp. As a rough guide 2017–2020 is 3-pin and 2021-on is 4-pin, but the changeover was mid-production, so always check the plug on your own car.
Can I put a 4-pin tail light on an older 3-pin Model 3?
Yes, with an adapter harness that converts between the two connector generations. Without an adapter the plug won't mate and the light functions won't work. Matching the connector when you order avoids the extra part.
Does the year decide which one I need?
Not reliably. The connector changed partway through production around 2020/2021, so same-year cars can differ. Use the year as a hint and confirm by counting the pins on your original connector.
Does MapleV stock both connector types?
Yes — we carry Model 3 tail lights and note the connector so you can match your car, cross-referenced to Tesla OE numbers and stocked in Greater Vancouver. If you're unsure, send us a photo of your connector and we'll confirm which one fits before you order.