It looks like if that fuse isburned out, that would still let the third brake light work. have a 98 dodge 12 valve i switched 3rd brake light to led. Yes Checked Bulbs, The two Lower back Lights Work. Modern cars have two or more fuse boxes. Now back up, sugnal, and tsil lights works, but NO Brake Lights. If it does not operate with the flashers, bad bulbs or sockets in the third-light are likely. Before replacing a switch check to see if it can be tested. If your third brake light works either way but the rear brake lights stop working when the truck is on its a faulty ground wire to the stop lamp relay. Corrosion is also a leading reason why the wiring becomes faulty. Check for a blown fuse and be careful, as many vehicles have more than one fuse box. After replacing the switch in the column, the brake lights worked beautifully for some time until recently. You can check and solve this problem by opening your car’s trunk and removing the taillights’ back cover. You need to take out your vehicle’s manual and find out the location of your brake light fuse. The third brake light works, located at the top above the rear glass. The third brake light does not flash with turn signals. They are in place so other drivers can spot you from behind and so that they can brake at a safe distance from you if you stop. It is possible that rodents have nibbled away at the wiring inside your car or that the wiring has deteriorated over time. After changing the lightbulbs and testing everything it turned out to be the light covering. Substitute a known good bulb, from the other side, to verify bulbs that cannot be confirmed otherwise. Full system voltage between the black wire and system ground suggest missing or broken ground. A quick test is to try the emergency-flashers, on vehicles that use the brake lights as flashers. If they do, the ground should be good. The CHMSL is on a dedicated circuit going through the brake switch so that if as in your case the two brake lights dont work you still have a brake light. A volt ohm meter or a LED test light will be needed for some tests. I'm guessing that the brake lights are switched on the negative side but I haven't seen the wiring diagram. Mechanics also have the proper equipment to test and solve your brake light issue. When the brake lights will not come on, the first thing to check is the third-brake light. But sometimes there are occasions where one of them works and the other doesn’t. Did you figure out the problem? A broken wire to or from the switch may also cause the lower brake-lights not to work. Other terminals may operate in a different manner. 2006 chevy truck, 4.8L 2wd Some of these had two fuses for brake lights. Press the brake pedal and they come on, release, and they go off. Over time, moisture from rain and snow seeps into small places where the wiring and the fuse box is located. Why is that? No matter what your problem, there is a reason for it and there is a solution. Inspect the bulb filament and replace any found bad. Pressing the pedal should cause the switch to move. The wiring diagram shows which terminals to check. The emergency flashers often use the same wiring, bulbs and sockets as the brakes. Therefore, it is necessary for both your taillights and brake lights to work. A good way is to measure the voltage is at the taillight when you are pressing the brake pedal, and doing the same thing at the brake pedal switch. Posted by josephpata on Mar 14, 2009. Thank You! A quick test is to try the emergency-flashers, on vehicles that use the brake lights as flashers. But if you have an older car, you want to check the light bulbs. Look in the trunk (if applicable). When the brake lights will not come on, the first thing to check is the third-brake light. If no 12 on blue wire oh boy. I replaced the bulb but still not working. Service data for the vehicle in question will normally identify the type. I checked the bulbs and fuses and they are ok. All other lights work. A voltage present between the wires and a ground means continuity on the ground wire should be checked. I’m here to give you answers to all your automotive questions and I hope that you enjoy our content. Anyways, spending some money here is better than paying a hefty fine in the future. Step 3 1 Comment; Flag; More. If that is the case then there is some other problem haunting you. Some modern vehicles may use digital sensors instead of a switch. If only the third light is out and the lowers still work, see if it will flash with the emergency-flashers. If these pads break or fall out, the pedal may not push the switch enough when released. It'll tell you the connector at the BCM and the wire color or pin number. If the bulb used in the brake light has gone faulty, it will not work when you depress the brakes. This way, your taillight will work but when you brake, but your brake lights won’t work. Tail light inop on passenger side. A bad brake switch is a really common problem when your brake lights are not working. Many modern third-brake lights use an LED and do not have bulbs that can be replaced. This is a strange problem since essentially the connections for both lights come from the same source. They light up extremely dim with flashers on. Many vehicles have small plastic pads, where the switch contacts the pedal, when released. I couldn’t get my brake lights to work even though my tail lights and Signal lights. Identify the correct fuse and replace it with a similar one. Parking lights and signals are working fine. If the contacts stick, the switch may continue supplying power to the lights, though it is released. With the pedal released, the brake-light switch should be pushed to its full off position. Taillights are necessary for nighttime driving. That leads us to the second reason why you could end up in this situation. There is no light on the dash telling me so, and besides I find it hard to believe all 3 went out at once. I need the Diagram that shows the Connector Locations on the Truck. Since using the turn signals is a pet pev of mine, I found out real quick that it was the turn signal switch. If you question that at all, confirm the back up lights work. Power and ground here, means the problem is in the second half of the circuit. I have no idea what is causing this problem. Be certain to seal any area check in this manner as the damaged wire may cause future problems. Finding such a shorted-circuit, is best left to a professional. Your vehicle’s taillights are working fine but when you press the brakes, the brake lights don’t come on. If the third brake light flashes, then most likely a fuse has gone bad. 2001 Chevy Impala rear brake lights are not working. Good fuses mean the most likely cause is the brake-light switch. Pull up on the brake pedal and if the lights go out, switch mis-alignment or pedal position error is the likely cause. Check a wiring diagram to identify which wires to follow and measure at. Lens cover cracked on dricer’s side. Finding a broken circuit or bad connector requires a wiring-diagram for the system being checked. A wiring diagram will supply color codes or terminal numbers and make identification easier. If you have 12 volts to the brake pedal switch – check if you get 12 volts out when you are pressing the switch. Lower Brake Lights Work, but Third Brake Light Does Not. Check any grounds the harness has in there. A switch may also slip out of position, increasing the space between the plunger and the pedal. So I suggestion is to turn the car on, since the car needs to be on to have the brake lights work, and just park it where you can see the brake lights from a wall or something. In rare instances, the brake booster may fail, and the pedal will not rise enough to contact the switch. Let’s have a look at the reasons for such a failure: New cars often use LED lights for the taillights. I've seen this switch knocked out of place before or even broken. Any recommendations to possibly fix the problem? In the illustration above, assume the red wire is the power lead for the brake lights and that the black wire is the ground for the circuit. Check if you have 12 volts to the brake pedal switch. These are far more difficult and may require professional service. Pushing the probe into a light socket will spread the contacts and cause the socket to fail. We are a free resource for well-researched and unbiased automotive information and product reviews. I noticed this morning that none of my 3 brake lights are working. I think the bulbs are good because the 2 filaments are still intact and the lights and turn signals still light up. A mechanic, on the other hand, is qualified to do such jobs. Here are two links. With the brakes still applied, less than 0.1 volts should show on the black wire, when checked to the body ground. A bad turn-signal switch may interrupt the brake light circuit when it should not. Jim, common problem. You can also win a free AGCO coffee cup, by reporting any errors you find, with this form. Jeep Liberty 2006 Ltd. Rear brake lights are not working. If the plunger of the switch does not contact the pedal, check for an adjustment. Then to rectify the problem, you would have to pay more for the parts. Brake lights seem extremely simple. If you have checked all the things listed above, all that is left to inspect is the wiring. Bad relay – Relays are switches that open or close the circuits electronically or electromechanically. Unplug the brake-light switch and if the lights stay on, a short circuit is the case. To test an analog brake-light switch for staying on, remove the switch and test for continuity between the terminals. Goes through a plug then to the led third light. We specialize in electrical diagnosis, minor or major. With a bad turn-signal switch, the third-light should still function. Some vehicles may have multiple switches on the brake pedal, and some switches may have more than one set of contacts. Check all the connections and make sure everything has been tied together properly. Either one light shines more than the other or the taillights completely switch off when you press the brakes. I attached the wiring diagram so you can see what I’m talking about. The stop light switch controls a single circuit to all three stop (brake) lights at the back of the car. 2002 Chevy Blazer, rear brake lights do not work but the third light above the window does. In such cases, it is always best to consult the vehicle’s user manual or, if you have some money to spare, a mechanic. There is a small switch fitted at your brake pedal to inform you when the pedal is pressed. With the brakes depressed, lightly touch the terminals with a voltmeter, to check for voltage. Check if you get voltage to the rear tail light bulb when pressing the brake pedal. Over time, wires and sockets are good because the brake lights not working but third light is filaments are still and... Gets answered our content holds the problem, there might also be a broken brake pedal while the engine on... One set of contacts to pay more for the lower lights do not work when you press brake! And they seem ok but they work just fine side, to check is the case, none of 3... 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