So I bought this 3rd LED brake flasher since I almost got rear ended about 4 months ago. After 3.5 months of hunting down the right connectors with the right wire colors, (yes im anal like that. Plus this way I can just unplug it and go back to factory if needed.) I went to install the module tonight. The factory wiring works obviously. The module works if I touch it to the battery. (The testing LED inside blinks 4 times then solid, like it should) The module will flash the 3rd brake light if I touch it's power to the battery. BUT If I connect the module to the brake power incoming from the hatch, I get no brake lights; the 2 main ones or the 3rd. If someone holds the brake petal down so there on, and I touch the module leads to that supply connector, all 3 lights go out with a tiny spark. like you overloaded and blew a fuse. Luckily it's circuit breaker acting and self-resets but Ive never seen such protection on a simple brake circuit. If it was powering something big, like a relay or light bulb (even a small 194 bulb), I could see it but were talking not even 1/2 an amp (I'm guesstimating) but I was tempted to pull out my oscilloscope to catch and measure the current pulse. So what can I do? it's to late to return the module. Try another? Try to build my own circuit?
Sounds like you are tripping the solid state current limiter in the car. They operate very fast. Which usually means a) your aftermarket device has a large inrush (sometimes due to a poorly designed internal power supply) or b) even after months of research, the wiring is backwards and a reverse biased protection diode in your device is forward biased. More likely a). Possible tests (or solution) might add a relay operated by the brake circuit with other constant battery power switched to the device by the relay contacts.
