Brake light voltage

[imported_OWDouglas]

Hi, I have a 2006 Honda Accord and tow a small trailer with it. I purchased a etrailer wiring kit and everything works except brake lights, after trouble shooting I seem to found the problem. I am only getting 8 volts off the brake light system. Brake lights on car are working fine but voltage is 8v, they are LED, I disconnected all trailer wiring and checked voltage, still only 8v at every socket (right, left, and center) but brake lights work on car. Checked wiring on trailer not a problem, trailer works with every other vehicle I hook up to. Any ideas on what could be causing this? Appreciate any help on where to check next.

 

[newbury]

When I got my first trailer I had to upgrade a piece in my E350 that controlled the flashers, I think it was the fuse.
Have you called etrailer?
They've been very helpful in the past.

 

[LD1]

Are the car brakes original or did you put LEDs on it?

Unless honda did something specific to reduce voltage, it should be the nominal 12-14v. If its not, its voltage drop through a bad connection somewhere

 

[BravoXray]

If the car lights are LEDs, the car is probably using PWM (Pulse Width Modulation) on the circuit for running/parking lights. Parking lights probably run at 50% or so duty cycle, brake and turn lights at 90-100%.
In the dark, with the Honda's parking lights on, sweep you eyes quickly from, left to right. If the light appears as a dotted line, that's the problem.

 

[bdhsfz6]

Are the trailer lights LED's? If so, try reversing the polarity of the trailer wiring. Some LED's are polarity sensitive.
Be aware that this can cause problems if the trailer wiring harness uses a ground return. Check first before changing anything.