I have the DEPO LED tail lights for my 1994 Accord LX, they work great and function properly when the headlights or running lights aren't on, but as soon as the headlights or running lights are on, the brake lights won't function when the brakes are pressed. They DO run with the headlights on, as running tail lights, but when the brakes are pressed, the tail lights turn off completely EXCEPT for the 3rd brake light, which does turn on.

Fuses are all good, relays are all good, ground is proper. I'm lost.

 

you might need load resistors keyword on might

 

Ive used DEPO company in the past and I've found that there service techs are pretty good at helping you out on line or on the phone..Give them a try.

WheelBrokerAng

 

LED's are diodes, they only work when a specific side is +12V and the other side is ground. incandescant bulbs work even if you swap polarity.

many switches (like brake switches) are switched ground. it is possible your brake pedal is causing an opposite polarity than the LED's want.

an inspection of the wiring diagram for the car would determine this.