Dodge D100 Brake Light Switch Guide (1975-1989)
Keep your classic Dodge safe and legal by fixing common brake light switch problems.
- The most common failures are brake lights that don't work or stay on constantly.
- The switch staying on is often due to it being pushed out of adjustment in its bracket.
- Standard Ignition is a reliable aftermarket brand for this part.
- This is a simple, inexpensive DIY repair that takes less than 30 minutes.
Is Your D100 Brake Light Switch Failing?
The brake light switch on these classic Dodge trucks is a common wear item. Because it's a mechanical switch that gets used every time you drive, it will eventually wear out or get knocked out of adjustment. The good news is that it's an easy and inexpensive part to replace.
Common Symptoms of a Bad Switch
Look for these signs that your brake light switch needs attention:
- Brake Lights Don't Work: This is the most obvious and dangerous symptom. If the switch fails internally, it won't complete the circuit to turn the lights on. Before replacing the switch, always check the bulbs and the fuse first.
- Brake Lights Stay On: This is a very common issue on 1970s and 80s Dodge trucks. The switch can get pushed backward in its mounting bracket, causing it to think the pedal is always pressed. This will drain your battery and confuse other drivers.
- Flickering Brake Lights: If the internal contacts are worn, the switch might make an inconsistent connection, causing the lights to flicker when you hold the pedal.
Pro Tip: Check the Adjustment First
Sometimes, the switch itself isn't broken, it has just been pushed out of position. This can happen after replacing a master cylinder or from heavy brake pedal use. Before buying a new part, get under the dash and see if you can pull the switch forward in its bracket to properly meet the pedal arm. Some owners add a zip tie or a small hose clamp around the body of the new switch to hold it more securely in the bracket.
Choosing the Right Aftermarket Switch
For a vehicle like the 1975-1989 D100, finding a new OEM (Original Equipment Manufacturer) part is nearly impossible. The aftermarket is your best and only realistic option. Quality aftermarket brands produce reliable parts that meet or exceed the original specifications.
Standard Ignition (Standard Motor Products): This is a well-regarded brand in the aftermarket that has been around for a long time. They are known for producing high-quality replacement parts with robust designs and good quality control. For a simple but crucial part like a brake light switch on a classic truck, Standard Ignition is a trusted choice that will fit and function correctly.
Estimated Cost to Replace
Replacing a brake light switch is one of the more affordable repairs you can do on your D100.
| Part Type | Cost Range |
|---|---|
| New Aftermarket (Standard Ignition) | $20 - $58 |
| Shop Labor | $50 - $100 |
| Total Cost (DIY) | $20 - $58 |
| Total Cost (Shop) | $70 - $158 |
Prices are estimates and can vary based on your location and specific retailer.
A Note on Wiring
On these older trucks, the power for the brake lights often runs through the turn signal switch in the steering column. If you replace the brake light switch and still have no brake lights, but your turn signals work, the problem could be in the turn signal switch or the wiring between the two components.
Frequently Asked Questions
Where is the brake light switch located on my D100?
The brake light switch is located under the driver's side dashboard. It is mounted on a bracket attached to the brake pedal assembly, positioned so the pedal arm makes contact with the switch's plunger.
Is this a hard part to replace myself?
No, this is a great DIY job for beginners. It requires basic hand tools and maybe 15-30 minutes of your time. The most difficult part is usually the uncomfortable position of working under the dash.
My new switch didn't fix the problem. What else could it be?
If a new switch doesn't solve the issue, check the simple things first: the brake light fuse and the bulbs. If those are good, the problem could be a bad ground, broken wiring, or an issue with the turn signal switch, which the brake light circuit passes through.
Were there any recalls on the D100 brake light switch?
No, there are no known recalls or technical service bulletins (TSBs) from the manufacturer for the brake light switch on the 1975-1989 Dodge D100. Recalls you may find online are for much newer Dodge vehicles or for different parts.
Technical Specifications
Mechanical, Plunger-Type, 2-Terminal Switch
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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.