The Bering MD23M front and rear turn signal bulbs both utilize a 1157 size bulb for proper operation. The replacement chart covers 1999 to 2000 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1157 is the bulb type used across all listed turn signal positions on the Bering MD23M, appearing in both the front and rear turn signal applications for the 1999-2000 model years.
The 1157 is a dual-filament bulb, meaning it contains two separate filaments within a single envelope, allowing it to serve two distinct lighting functions at different wattages.
The 1157 operates on a 12-volt electrical system and draws 21 watts on its primary filament and 5 watts on its secondary filament, reflecting the higher power demand of active signaling versus a lower-intensity standby or parking function.
The 1157 uses a BAY15d bayonet base, which is an offset twin-pin base design. The offset pin placement is a deliberate fitment feature that prevents the bulb from being inserted in the wrong orientation, ensuring the correct filament aligns with the intended circuit.
The 1157 is classified as an ANSI standard bulb recognized in both the United States and Canada, indicating it conforms to a defined set of dimensional and electrical specifications shared across those markets.
Because the front and rear turn signal positions on the Bering MD23M both use the 1157, a single bulb type serves all four turn signal sockets across the vehicle for the 1999-2000 model years.
The BAY15d base of the 1157 is not interchangeable with single-filament bayonet bases such as the BA15s, and substituting a single-filament bulb in a socket designed for the 1157 would result in the loss of one of the two intended lighting functions.