Why do my turn signals stop flashing when I apply the brake?

Check your light bulbs, the two filament bulbs can shorten out on a filament when the brake is applied. Make sure you have the right bulbs in and check the wiring harness on your lights and take a look inside the light assembly for any short circuit. Also any addition like the third brake light and, like mayer said, a trailer light plug that is shortened can do it too. Good Luck to you

I am having the same problem with my 02 jeep liberty. The blinker works just fine, but as soon as I turn the head lights on and apply the brake they don't flash just stay on. But when the headlights are off they work just fine when applying the brake.

I have a similar problem, my right hand turning signal blink faster when I apply brakes! pls assist skhinero@gmail.com

I have a 05 monte carlo, my problem is my turn signals are going crazy, they work just fine while the car is in park, after putting in gear they stop work, also when i turn my head lights on thats when they work but they blink real fast, last thing my fog lights are very dim, I've replaced and checked fuses and bulbs, still same issues, can someone help, Thans Randy

All of these problems mentioned can be the result of a bad ground. When you operate both blinkers and brake lights and the blinkers stop blinking, it’s because the circuit is not good enough to operate both lights. Bad ground. Same with headlights and blinkers. Probably the same with fog lights. Easy solution is the add an additional ground for the tail lights. Tail lights are the farthest away from the battery. Find the ground wire in each tail light assembly and add an additional wire and connect it to a good solid metal point and your problems will be all gone!!

Mine is doing the same especially when below freezing. The CRAZIEST thing is when I turn my right turn signal on I lose acceleration and my car won’t go. I have to turn the turn signal off and let my foot off the gas then reapply for acceleration. It has now Gizmo in water as I now have recently had my air conditioning stop blowing cold, check engine light come one, engine with a down arrow come on and I have lost half of my acceleration as it is driving like it only has four cylinders firing. Once up to speed drives fine. There are 16 other codes popping off now. One day they all started working again then 2 months later everything went back out again. Also as I am typing this my dome light flickered twice and went back off after the lights have been out and sitting here for at least 10 minutes. It recently stopped starting after three hard starts. I changed the starter and upon completion I now get no power to my windows, my cluster doesn’t come on, my stereo doesn’t come on and and I only get battery light to come on when I turn the key. I took my dash apart and my rear cig lighter worked as I used it to plug a couple things in over the course of time. After inspecting everything and putting dash back together no lighter works now (2 in front 1 in back) could the same thing be causing my issue? I’ve been stranded for 2 months now. It’s my only car and I can’t get to pick my son of 3 years up three days out the week. It’s beginning to take a toll on him and myself. I have all tools necessary to fix whatever needs fixed however I can’t find the culprit so I can fix it. 2006 Chevy Trailblazer 4x4 6 cylinder the 480 or 460 engine.