I have a 2010 Colorado and my brake lights, all 3, aren’t working. I’ve replace the switch on the right side of brake pedal, the fuses and bulbs have been checked by auto parts store and are fine. Could it be the fuse box or bad brake light circuit?

if all the brake light bulbs are ok it could be the brake light switch which is normally on the brake pedal hope this helps.also check if theres a fuse for your brake lights some vehicles do.

Try checking your brake switch which is located right above your brake pedal. It is electrical and has a spring loaded pin that comes out when pedal is pushed and contracts in when pedal is released. When its in it turns off the brake lights.

Go to your brake pedal and see if your brake switch is working properly,push it in with hand and see if switch engages and releases when you let up on pedal.It is adjustable.Also check your bulbs to see if the bulb holder is corruded.Check wiring around bulb too.

Check System Fuse - A fuse is used to protect the brake light circuit from amperage overload. If the fuse has failed it will not allow the electrical current to continue to the brake lights. To check the fuse, first locate the brake light system fuse in the fuse panel which is either under the dash or under the hood in the power distribution center. Connect the test light to a ground like an engine or dash bracket and turn the ignition key to the "on" position. Using the test light probe both sides of the fuse. If the test light illuminates on both sides the fuse is okay continue onto the next step. If one side of the fuse illuminates the fuse has failed and needs to be replaced. If the fuse fails as soon as it is replaced or when you apply the brake pedal the brake light electrical circuit is shorted to ground. Rarely a system short can occur, a car repair manual is needed to find the wiring schematic for the brake light circuit. Once the brake light wiring has been located inspect and repair as needed.

Check Brake Light Bulbs - All cars have three brake light bulbs that create the brake light illumination affect. If all of these brake light bulbs fail no brake light operation will occur. I know what you're thinking, you might say all three brake lights at once? But in reality one brake light went out at a time and you did not notice. People only tend to notice something when they almost run into the back of your car to help persuade them to inform you the brake lights aren't working. Remove any of the brake light bulbs to confirm the bulb is okay or burned. After the bulb has been removed inspect the filament and replace if failed. If the brake light bulbs are okay continue to the next step.

Checking the Brake Light Switch - A control switch is used to connect the brake light electrical circuit. This switch is located near the brake pedal lever. Basic switches have just two wires, power in and power out to the turn signal switch. Use a test light that is grounded and with the key in the "on" position test for power at one side (wire) of the switch, then press the brake pedal while testing the opposite side (wire). It should illuminate the test light, if electrical power is connected through the switch go to the next step. If no power is detected through the switch the brake light switch has failed and replacement is required. If your car is equipped with more than two wires integrated into the brake light switch a car repair manual is needed to locate the proper brake light circuit wiring.

Bulbs are just like a fuse to for they blow out like a fuse. You have a brake light switch mounted near the brake pedal. Check that switch out with a OHM meter. Just unplug the switch and feed the Ohm meters contacts into the switch. Then push the brake pedal down to see if it completes the circuit. If a OL reading is showing at all times the switch is bad and needs to be replaced

check all your fuses if fuses are good check brake lite bulbs see if they are blown. if bulbs are good get a test lite see if you have power to the bulb sockets have friend apply brake pedal you test power going into bulb socket if you have no power brake lite switch behind brake pedal could be burnt out. p.s dont forget to check all fese relays when checking your fuses.

sounds like a faulty brake light switch located down by the brake pedal

Look above your brake pedal and you will see your brake switch up along your brake pedal arm. It will either be between the brake arm and the firewall so when you brake it pushes the switch in. Or it will be between the dash and the brake arm so when you brake it pulls the switch out. Most likely this switch needs to be replaced

Troubleshooting Procedures - Read Completely Before Beginning
(American Car) All Brake Lights Not Working

• Check System Fuse: A fuse is used to protect the brake light circuit from amperage overload. If the fuse has failed it will not allow the electrical current to continue to the brake lights. To check the fuse, first locate the brake light system fuse in the fuse panel which is either under the dash or under the hood in the power distribution center. Connect the test light to a ground like an engine or dash bracket and turn the ignition key to the "on" position. Using the test light probe both sides of the fuse. If the test light illuminates on both sides the fuse is ok continue onto the next step. If one side of the fuse illuminates the fuse has failed and needs to be replaced. If the fuse fails as soon as it is replaced or when you apply the brake pedal the brake light electrical circuit is shorted to ground. Rarely a system short can occur, a car repair manual is needed to find the wiring schematic for the brake light circuit. Once the brake light wiring has been located inspect and repair as needed.
  
• Check Brake Light Bulbs: All cars have three brake light bulbs that create the brake light illumination affect. If all of these brake light bulbs fail no brake light operation will occur. I know what you're thinking, you might say all three brake lights at once? But in reality one brake light went out at a time and you did not notice. People only tend to notice something when they almost run into the back of your car to help persuade them to inform you the brake lights aren't working. Remove any of the brake light bulbs to confirm the bulb is ok or burned. After the bulb has been removed inspect the filament and replace if failed. If the brake light bulbs are ok continue to the next step.
  
• Checking the Brake Light Switch: A control switch is used to connect the brake light electrical circuit. This switch is located near the brake pedal lever. Basic switches have just two wires, power in and power out to the turn signal switch. Use a test light that is grounded and with the key in the "on" position test for power at one side (wire) of the switch, then press the brake pedal while testing the opposite side (wire). It should illuminate the test light, if electrical power is connected through the switch go to the next step. If no power is detected through the switch the brake light switch has failed and replacement is required. If your car is equipped with more than two wires integrated into the brake light switch a car repair manual is needed to locate the proper brake light circuit wiring.

after u check all the bulb try to check the fuses if its ok change the brake light switch which is located front of the brake pedal