How to Replace Your Side Mirror Turn Signal Bulb in 5 Minutes

When it comes to safe driving, turn signals are important. They help you communicate to drivers around you that you’re about to turn or switch lanes so they can give you space. Turn signals occasionally fail, though, because the bulbs burn out over time.


If you find that one of your side mirror turn signals no longer works, you can quickly fix the problem at home with this tutorial. You could pay a shop to replace the turn signal bulb, but it’ll cost a pretty penny. That would be pretty pointless for a quick project that’s quite easy to do yourself with only an Allen wrench.

So how do you replace the turn signal bulb on your GMC vehicle? We’ll show you, but first you need to order a replacement bulb or lens.

Ordering a Replacement Turn Signal Bulb

Replacement bulb

You need a #194 bulb. You can buy one at Walmart or Amazon, but we recommend getting a genuine OEM bulb because they’re designed with quality, longevity, and precise fitment in mind.

Does the side mirror turn signal lens also need to be replaced? GMC sells OEM turn signal lenses with a bulb built in. Look up your GMC model in our catalog to find the right part number. You’ll see a variety of lenses for your car. You want to find one that’s a part of your mirror assembly.

The Only Tool You’ll Need

This project is so easy that there’s only one tool you’ll need: an Allen wrench. Specifically a 5/64" Allen wrench.

Steps to Replace Your Turn Signal Bulb

GM mirror signal

This set of instructions is for the second generation GMC Envoy (2002-2009), but you should be able to follow it with another GMC model without much trouble.

  1. Push the mirror assembly all the way forward
  2. With an Allen Wrench, remove the screw underneath the mirror.
  3. Carefully pull the lens down until it releases
  4. Turn the squares on the connector until they line up, then unplug it
  5. Gently remove the connector from the lens; you'll see a bulb attached
  6. Take the old bulb out and replace it with the new one
  7. Put the connected bulb back into the lens and lock in place
  8. Screw the lens back into the mirror assembly
  9. Move the mirror assembly back

That’s all! It’s a quite easy process. Please contact us if you have any questions about finding the right bulb or lens for your car, or if you need assistance replacing your bulb.