Chevrolet Blazer Ignition Switch Guide for 1974-1998 Models
Having trouble starting your Blazer or dealing with strange electrical issues? Your ignition switch could be the problem.
- Verify if you have a full-size K5 or a smaller S-10 Blazer; the parts are very different.
- For 1995-1998 models, be aware of the PassLock anti-theft system, which may require a relearn procedure.
- Symptoms range from a complete no-start to intermittent stalling and flickering lights.
- ACDelco and Standard Motor Products are top-tier brands, while Dorman offers a good value alternative.
Understanding the Two Main Eras of Blazer Ignition Switches
The 1974-1998 year range for the Chevrolet Blazer covers two very different vehicles: the full-size K5 Blazer (until 1994) and the smaller S-10 Blazer (starting in 1983). It is critical to identify which Blazer you own before ordering a part.
- 1974-1994 Full-Size K5 Blazer: These trucks typically use a mechanical ignition switch mounted on the steering column, away from the key lock cylinder. A rod connects the lock cylinder you turn with your key to this electrical switch. Problems can arise in the lock cylinder, the connecting rod, or the switch itself.
- 1983-1998 S-10 Blazer: The ignition switch design in these models is often more integrated. Later models, especially from 1995 onwards, may feature anti-theft systems like PassLock. The PassLock system uses a resistor inside the ignition components to verify the correct key is being used. A failure in this system can prevent the truck from starting and may require a specific relearn procedure or bypass after replacement.
Common Ordering Mistake
The most common mistake is ordering a switch for the wrong Blazer. A switch for a 1978 K5 Blazer is completely different from one for a 1998 S-10 Blazer. Always verify your exact year and model (K5 or S-10) before purchasing. Also, note whether your steering column has a tilt-wheel function, as this can affect which part you need.
Symptoms of a Failing Ignition Switch
A bad ignition switch can cause a variety of confusing problems. Because it controls so many electrical systems, the symptoms can seem unrelated.
- Key Won't Turn or is Stuck: The key may feel stubborn or get completely stuck in one position. This can be a problem with the lock cylinder or the switch itself binding.
- Engine Won't Start: You turn the key and get nothing—no click, no crank. All the lights might come on, but the starter doesn't engage.
- Stalling While Driving: The engine can suddenly shut off while you are driving. This is a serious safety issue, as it also causes a loss of power steering and power brakes.
- Flickering Dashboard Lights: You might see the dashboard lights flicker, or the voltage gauge jump around wildly. Accessories like the radio may cut out and then come back on.
- Security Light On: On later models with PassLock, a failing switch can trigger the security light, preventing the engine from starting for a 10-minute timeout period.
Choosing the Right Aftermarket Ignition Switch
When your original switch fails, you have several aftermarket options. Quality can vary, so it's important to choose a brand that fits your needs and budget.
Premium Aftermarket Brands (OEM Quality)
- ACDelco: As the original equipment manufacturer (OEM) for General Motors, ACDelco parts are considered the benchmark for fit and function. Choosing ACDelco is the closest you can get to the original part that came with your Blazer.
- Standard Motor Products (SMP): A highly respected brand in the automotive industry, SMP parts are known for meeting or exceeding OE specifications. They use quality materials like copper alloy conductors and perform 100% testing on their switches.
Standard Aftermarket Brands (Good Value)
- Dorman: Dorman is a popular brand that offers a wide range of parts, often at a lower price than OEM. While some users are cautious about Dorman electrical parts, they are a common replacement and often include improvements over the original design. They are a cost-effective solution that generally matches the fit and function of the original.
- Rostra Powertrain: Rostra is a known manufacturer of automotive components, though less commonly mentioned for this specific part in forums. They generally produce reliable parts for various vehicle systems.
Budget-Friendly Brands
- Replacement / URO Parts: These brands offer the most budget-friendly options. They can be a good choice if you need to get your vehicle back on the road for the lowest cost. However, long-term durability may not match that of premium brands.
Pro Tip: Check the Lock Cylinder First
Sometimes, the problem isn't the electrical switch but the mechanical lock cylinder where you insert the key. If your key is worn out or the cylinder tumblers are damaged, it can cause similar symptoms. Consider if you need just the switch, just the lock cylinder, or a complete assembly.
Cost of Replacing a Chevrolet Blazer Ignition Switch
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Ignition Switch | $21 - $155 |
| Shop Labor | $100 - $250 |
| Total Estimated Cost | $121 - $405 |
Costs are estimates and can vary based on your vehicle's specific model, your location, and the repair shop.
Frequently Asked Questions
Can I replace the ignition switch myself?
Yes, this is a DIY-feasible job for someone with moderate mechanical skill. For older K5 models, it involves working under the dash on the steering column. For later S-10 models, you will need to remove steering column covers and may need special tools like Torx bits. It is crucial to disconnect the battery first to ensure safety.
What is the difference between the ignition switch and the lock cylinder?
The lock cylinder is the mechanical part you put your key into. The ignition switch is the electrical component that the lock cylinder controls, often via a connecting rod or direct linkage. You can sometimes buy them separately or as a complete assembly.
Are there any recalls on the Blazer ignition switch?
While GM had a massive, well-publicized ignition switch recall for many 2003-2011 model year cars, the 1974-1998 Chevrolet Blazer was not included in that specific recall campaign. However, some later GM trucks had issues with ignition lock actuators sticking. Always check for any open recalls on your specific vehicle using its VIN on the NHTSA website.
Do I need to reprogram my Blazer after replacing the ignition switch?
For most models in this year range (1974-1994), no reprogramming is needed. However, for 1995-1998 models with the PassLock anti-theft system, a "relearn" procedure may be necessary after replacement to allow the vehicle to recognize the new component and start. This usually involves a sequence of turning the key and waiting for a specific amount of time.
Technical Specifications
OEM Part Numbers: 1990109 1116683 1116695 1116704 1116709 1116711 1116712
Varies significantly by year and model (K5 vs. S-10). Early models are column-mounted electrical switches actuated by a rod. Later S-10 models are more integrated and may include PassLock anti-theft technology. Connectors can have between 7 and 13 terminals depending on the application.
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.
- 🛍️ Shop This Part
- Understanding the Two Main Eras of Blazer Ignition Switches
- Common Ordering Mistake
- Symptoms of a Failing Ignition Switch
- Choosing the Right Aftermarket Ignition Switch
- Premium Aftermarket Brands (OEM Quality)
- Standard Aftermarket Brands (Good Value)
- Budget-Friendly Brands
- Pro Tip: Check the Lock Cylinder First
- Cost of Replacing a Chevrolet Blazer Ignition Switch
- Frequently Asked Questions
- 🎟️ Get 5% Off