1156-1157 LED Bulb Series
Factory-direct 1156/1157 LED bulbs (BA15s/BAY15d) for turn signal, brake and tail lights. Single and dual filament, CANbus available.
1156 / 1157 LED Bulbs: BA15s & BAY15d Bayonet Turn Signal, Brake & Tail Light Replacements
The 1156 and 1157 are the two most widely used bayonet-base bulbs in automotive exterior lighting, found on cars, trucks, trailers, motorcycles, and recreational vehicles worldwide. The 1156 (BA15s) is a single-contact, single-function bulb used for turn signals, reverse lights, and daytime running lights. The 1157 (BAY15d) is a dual-contact, dual-function bulb that combines brake and tail light, or turn signal and running light, in a single housing. MIDCARS manufactures both in-house, factory-direct, with standard, CANbus, and dual-color switchback versions to cover every replacement and upgrade scenario.
1156 vs 1157: What's the Difference?
The two bulbs look similar but are not interchangeable. The difference comes down to the number of bayonet pins, the contact type, and the number of circuits each bulb drives.
| Feature | 1156 (BA15s) | 1157 (BAY15d) |
|---|---|---|
| Base type | BA15s — single-contact, parallel pins | BAY15d — dual-contact, offset pins |
| Circuit | Single circuit (one function) | Dual circuit (two functions) |
| Brightness levels | One level | Bright (brake/turn) + dim (tail/running) |
| Typical use | Turn signal, reverse, DRL | Brake + tail combo, switchback turn + DRL |
| Common cross-reference | P21W, 7506, 1073 | P21/5W, 7528, 2357 |
Because the 1157 has offset pins and two contacts, it only seats one way in the socket and cannot be forced into a 1156 socket (and vice versa). Always confirm your base before ordering, and check the vehicle owner's manual or the marking on the old bulb.
How to Choose the Right 1156 / 1157 LED Bulb
- Confirm the base. Single-contact BA15s = 1156; dual-contact BAY15d = 1157. Read the old bulb or check the socket.
- Single or dual function. If the socket drives two brightness levels (brake + tail, or turn + running), you need a dual-function 1157; a single-function 1156 will not behave correctly.
- Voltage. Standard automotive is 12V; trucks and heavy-duty vehicles often run 24V. We build both 12V and 24V versions with a wide, stable operating range.
- Color temperature. 6500K white for modern crisp output, 3000K warm white for a classic halogen look, and 1800K amber for turn signals where regulation requires amber output.
- CANbus or non-CANbus. CANbus (error-free) versions include a built-in load to prevent hyper-flash and dashboard error warnings on vehicles with lamp-out detection; non-CANbus versions suit simple circuits and classic vehicles.
- Standard or switchback. Switchback dual-color versions show white as a running/DRL light and automatically switch to amber when you signal, giving a clean two-in-one upgrade.
Common Applications
- Front and rear turn signals
- Brake and tail light combinations
- Reverse / backup lights
- Daytime running lights (DRL)
- Trailer, RV, and motorcycle lighting
- 24V truck, bus, and heavy-duty vehicle lighting
Why Source 1156 / 1157 LED Bulbs from MIDCARS
- Factory-direct manufacturing in Dongguan, China — no middlemen, competitive wholesale pricing, and full control over quality.
- Certified compliance — CE-LVD, CE-EMC, and RoHS certificates with full test reports available to verified buyers.
- CANbus error-free versions that eliminate hyper-flash and dashboard warnings.
- Dual-color switchback options for white/amber two-in-one upgrades.
- Long lifespan and instant full brightness with low heat generation, suitable for continuous turn-signal and brake cycling.
- Flexible ordering — standard stock from 5 pairs; custom packaging available with a 5,000-piece packaging MOQ drawn down across repeat orders.
LED vs Halogen: Why Upgrade to LED?
Upgrading from halogen to LED delivers measurable benefits for your customers. LED bulbs light up instantly—critical for brake lights, where the fraction-of-a-second faster response gives following drivers more reaction time and reduces rear-end collision risk. LEDs also run cooler, last far longer than halogen filaments, draw less power (reducing load on wiring and alternators), and resist the vibration and constant cycling that quickly kills halogen bulbs in turn-signal and brake applications. For 1156/1157 positions that flash and cycle constantly, the durability difference is especially pronounced.
Installation Notes
1156/1157 LED bulbs are plug-and-play replacements: remove the old bulb, insert the LED into the socket, and test before final assembly. If a vehicle uses a mechanical flasher relay, pair non-CANbus versions with a compatible LED flasher relay to avoid hyper-flash. Always confirm the base type (BA15s vs BAY15d) before installation.
Frequently Asked Questions
Will an LED 1157 cause hyper-flash?
LED bulbs draw far less current than halogen, so vehicles with flasher-relay or lamp-out detection may hyper-flash or show a warning. Our CANbus (error-free) versions include a built-in load to prevent this. For older vehicles with a mechanical flasher relay, a compatible LED flasher relay may still be recommended.
Can I use a 1156 bulb in a 1157 socket?
No. The 1156 has a single contact and the 1157 has dual offset contacts, so the two bases are physically and electrically different and are not interchangeable. Always match the base to the socket.
Which color temperature is best for turn signals?
For turn signals, regulations in most regions require amber output through an amber lens or amber LED. We recommend 1800K amber for signaling, or a dual-color switchback version when you want white running light and amber turn signal in one bulb.
Do you offer 24V versions for trucks and buses?
Yes. In addition to standard 12V automotive versions, we manufacture 24V 1156/1157 bulbs for trucks, buses, and heavy-duty vehicles. Contact us with your voltage and application, and we will recommend the correct model.
What is your minimum order quantity?
Standard stock starts from 5 pairs for testing and sampling. For custom packaging, the packaging run has a 5,000-piece MOQ, which is pre-funded and drawn down across your repeat orders. Contact sales02@zhishanled.com for a quotation.
