I just got a piece of **** car, and whenever i brake, or when i turn the left side blinker on, the taillight dims instead of getting brighter. Also, the left turn signal blinks slower than the right turn signal. Even on the dash, the little arrow blinks slower than on the right. I compared the actual bulb with the other, and its dimmer when lit. I JUST bought new bulbs twenty minutes ago, even the old bulbs did this. So i don‘t know if i have a short in the wire or what, i already looked back by the light and all the wires are old, but look fine. I don‘t know if somewhere inside the car frame something happened or up where they go to the battery, but the whole left side lighting system is screwed up. Any help before i call the auto shop?
If there was a short, it would blink faster because of more current passing through the flasher relay. Sounds like you have corrosion somewhere in the system, causing increased resistance. No choice but to start at the bulbs, and grounds, and clean every connection along the way.