Chevrolet Blazer Headlight Dimmer Switch Guide: 1986-1991
Having trouble with your high beams or low beams? Your dimmer switch is the likely culprit.
- The dimmer switch is on the steering column, not the dash, and controls high/low beams.
- Failure symptoms include loss of high/low beams or flickering headlights, which is a critical safety issue.
- Replacement is a manageable DIY task but requires working in a tight space under the dash.
- A quality aftermarket brand like Standard Ignition is a reliable and cost-effective choice for this repair.
Symptoms of a Failing Headlight Dimmer Switch
A bad dimmer switch can create dangerous driving conditions. Because it controls which headlight filament gets power, failure often means a partial or total loss of forward lighting. Watch for these specific signs in your Blazer:
- No Low Beams or No High Beams: The most common symptom is losing one of the two functions. You might pull the lever and nothing happens, or the lights stay stuck on one setting.
- Headlights Cut Out Intermittently: The internal contacts can wear out, causing the headlights to flicker or shut off completely while driving. This is a major safety hazard.
- No "Click" Feeling: A good switch makes an audible click when you pull the lever. If that click is gone, the switch's mechanical plunger has likely failed internally.
- High Beams Stuck On: The switch can fail in the high-beam position, which can blind other drivers.
Critical Safety Warning
If your headlights are flickering or cutting out, the vehicle is not safe to drive at night or in poor visibility. This problem will not fix itself and can lead to a complete loss of headlights without warning. Replace the switch as soon as possible.
Choosing the Right Aftermarket Dimmer Switch
For a classic truck like the 1986-1991 Blazer, finding new original equipment (OEM) parts from ACDelco can be difficult. The most reliable and available option is a quality aftermarket part.
Brand Spotlight: Standard Ignition (Standard Motor Products)
Standard Ignition is a well-known brand often trusted by professional mechanics. Their switches are designed to be direct-fit replacements that match the original part's form and function. They typically use quality materials like copper alloy conductors to ensure good electrical performance. For this specific application, where the part is a simple mechanical switch, a reputable aftermarket brand like Standard is a dependable choice.
Headlight Dimmer Switch Replacement Cost
The cost to replace the dimmer switch is reasonable, with the part itself being the main expense. If you have it done at a shop, expect to pay for about an hour of labor.
| Part Type | Estimated Part Cost | Estimated Shop Labor Cost |
|---|---|---|
| New Aftermarket (Standard Ignition) | $45.63 | $100 - $150 |
| New OEM (ACDelco) | $50 - $75 (if available) | |
| Used OEM | $15 - $30 |
Pro Tip: While replacing the switch, it's a good time to inspect the wiring connector for any signs of melting or corrosion, which can also cause lighting issues.
Frequently Asked Questions (FAQ)
Is the headlight dimmer switch the same as the headlight switch?
No. The main headlight switch is the knob on the dashboard that you pull to turn on the parking lights and headlights. The dimmer switch is located on the steering column and is activated by the turn signal lever to switch between high and low beams.
Can I replace the dimmer switch myself?
Yes, this is a feasible DIY job for someone with basic mechanical skills. It involves working in a tight space under the dashboard and may require removing the lower dash panel to get access. The steering column might need to be unbolted and carefully lowered to reach the switch. Be careful not to damage the shifter cable if you have an automatic transmission.
Why do my dash lights dim but my headlights don't change?
This is normal. The rotary dial on the main headlight switch controls the brightness of your instrument panel and dashboard lights only. It has no effect on the headlights. The high/low beam function is controlled separately by the dimmer switch on the steering column.
My new switch is installed but it's not working correctly. What's wrong?
The switch may need to be adjusted. The mounting holes on the switch are often slotted, allowing it to slide up or down the steering column. This adjustment changes its position relative to the actuator rod. Loosen the mounting nuts, slide the switch until it clicks properly when the lever is pulled, and then retighten the nuts.
Technical Specifications
OEM Part Numbers: 1995799 D6230
Column-mounted mechanical switch with a plunger activated by a rod connected to the turn signal lever.
We Have This Part in Stock
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.
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