Guide to the 1970-1978 Buick Century Headlight Switch
Don't get left in the dark—understand the signs of a failing headlight switch in your classic Century.
- A hot-to-the-touch headlight switch is a critical failure sign requiring immediate replacement.
- Symptoms like flickering lights or non-working dash dimmers are classic signs of a failing switch in a 70s GM vehicle.
- Standard Ignition is a well-regarded aftermarket brand for this part, offering a higher quality option.
- Always inspect the wiring connector for melting or damage when replacing the switch.
Is Your Headlight Switch Failing?
For cars like the 1970-1978 Buick Century, the headlight switch is a common failure point due to its age and design. These switches handle significant electrical current, which generates heat. Over decades, this heat can cause internal components to degrade, leading to a variety of electrical problems.
Common Symptoms of a Bad Headlight Switch:
- Flickering or Intermittent Headlights: Your headlights may turn on and off by themselves while driving. This is often caused by a worn-out internal circuit breaker in the switch.
- Lights Don't Turn On: You might pull the switch and nothing happens, or only the parking lights work.
- Dashboard Lights Malfunction: The instrument panel lights may not dim properly or may not work at all. This points to a failure of the internal rheostat.
- Switch is Hot to the Touch: A switch that feels unusually warm or hot is a serious warning sign. This indicates high resistance and a potential fire hazard. You might also notice a faint burning plastic smell.
- Dome Light Issues: If the dome light won't turn on when you rotate the switch knob, the switch is likely faulty.
A Note on Other Potential Issues
While the headlight switch is a frequent culprit, similar symptoms can be caused by a bad ground connection, a faulty high/low beam dimmer switch on the floor, or issues in the wiring harness itself. It's always a good idea to check fuses and ensure the wiring connector at the switch isn't melted or corroded.
Choosing the Right Aftermarket Headlight Switch
Since new original equipment (OEM) switches from GM are no longer produced for this vehicle, you will be choosing from aftermarket options. For your Century, two main tiers are available.
Brand Options:
- Standard Ignition (Standard Motor Products): This is a well-known and respected aftermarket brand that has been around for decades. Their parts are generally considered to be of good quality, often meeting or exceeding original specifications. For a critical component like a headlight switch, Standard Ignition is a reliable choice.
- Replacement: This brand represents a more budget-friendly option. While it may not have the long-standing reputation of Standard Ignition, it provides a functional replacement that gets the job done at a lower cost. For many owners, this is a perfectly acceptable solution.
Pro Tip: When you replace the switch, carefully inspect the plastic wiring connector that plugs into it. If the old switch was overheating, it may have melted the connector or its terminals. A damaged connector will cause the new switch to fail prematurely.
Headlight Switch Cost for 1970-1978 Buick Century
| Part Type | Price Range |
|---|---|
| New Aftermarket | $31.80 - $58.42 |
| Shop Labor | $90 - $150 |
Frequently Asked Questions
Can I replace the headlight switch myself?
Yes, this is a DIY-friendly job for most people with basic tools. The process typically involves removing the lower dash panel to access the switch. The switch is held in by a retaining nut, and the knob is released by pressing a small spring-loaded button on the switch body itself. The main challenge is often working in a tight space under the dashboard.
Why do my dash lights flicker or not dim correctly?
This is almost always caused by a failure of the rheostat coil inside the headlight switch. This coil allows you to adjust the brightness of the instrument lights. Over time, it can break or corrode, causing the dimming function to stop working.
Is it normal for the new headlight switch to get warm?
A slight warmth can be normal because the switch handles a lot of electrical current. However, it should never become hot to the touch. A hot switch indicates excessive resistance, which could be a problem with the new switch or a separate issue in the vehicle's wiring.
My headlights work, but my high beams don't. Is that the switch?
It could be, but it's more likely the floor-mounted dimmer switch. All power for the headlights runs through the main headlight switch first, then to the dimmer switch which toggles between high and low beams. If only one beam is out, the dimmer switch is the first place to check.
Technical Specifications
OEM Part Numbers: 1995111 1995112 DS155
Dash-mounted pull/push and rotate switch. Controls headlights, parking lights, instrument panel dimming, and dome light.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.