Take charge of your classic's headlights with the Standard Ignition Headlight Switch DS-121, a Chevrolet BK switch that is a direct-fit replacement for the listed applications: the 1940 Chevrolet KC, 1940 Ford Deluxe, 1940 Ford Sedan Delivery, and the 1942 Chevrolet BK, BL and BN. The headlight switch is the driver's control for the headlights. It opens and closes the electrical path that powers the lamps when you operate it.
- Quality control throughout: Standard Ignition is a global manufacturer of original equipment ignition products. It maintains complete quality control across the manufacturing process, from componentry to the finished product.
- Copper alloy conductors: Used for strong electrical conductivity with low resistive losses.
- 100% tested: Standard Ignition tests every switch to verify both mechanical and electrical switching performance.
- Built for the technician: A robust design and high-grade materials are intended to meet the stringent demands of today's service professional. They are backed by decades of research and development focused on what technicians need.
Signs this switch may need replacing include headlights that won't come on, lights that flicker or cut in and out, and a switch that feels loose or binds. Fuses, wiring, bulbs and grounds can cause similar symptoms, so diagnose the lighting circuit first. If the switch is at fault, the DS-121 replaces it. For engine-specific details, see the "Vehicles it fits" section.
Interchange: 810274 · 916357 · J810274 · J916357 · S141 · SW8 · HL6049 · 12302012 · 1972302 · 1994017 · 1995021 · UNIVSW1 · HL6049SB
Product information is for general reference and may contain errors. See our Disclaimer.
This part cross-references / interchanges with the following part numbers:
810274, 916357, J810274, J916357, S141, SW8, HL6049, 12302012, 1972302, 1994017, 1995021, UNIVSW1, HL6049SB
Frequently Asked Questions
Which vehicles does the Standard Ignition DS-121 fit?
It is listed for the 1940 Chevrolet KC, 1940 Ford Deluxe, 1940 Ford Sedan Delivery, and the 1942 Chevrolet BK, BL and BN. See the "Vehicles it fits" section for engine details.
What does a headlight switch do?
It is the driver's control for the headlights. It opens and closes the electrical path that powers the lamps when the switch is operated.
What are signs my headlight switch may need replacing?
Signs include headlights that won't turn on, flicker, or work intermittently, and a switch that feels loose or sticks. Check fuses, wiring, bulbs and grounds too, since they can cause similar symptoms.
Is the DS-121 tested?
Yes. Standard Ignition 100% tests its parts to verify both mechanical and electrical switching performance.
What part numbers does the DS-121 interchange with?
It cross-references 810274, 916357, J810274, J916357, S141, SW8, HL6049, 12302012, 1972302, 1994017, 1995021, UNIVSW1 and HL6049SB.
