A 2021 updated Trailer hitch & brake controller thread

[Attacking Mid]

Mine never had a "clean" signal from any wire in the LCM. There are two wires in the LCM that give a brake signal, but one also pulses with the turn signal, and the other seems to be slightly under-voltage, which results in my Prodigy2 controller display spazzing out. Despite the display issues, the controller DOES work, so I put up with it for a couple years. Supposedly, you can find a clean source at the high-mounted brake light on the rear hatch. I never bothered, so I can't verify.

AM.

[Lowblock]

Originally Posted by Attacking Mid

Mine never had a "clean" signal from any wire in the LCM. There are two wires in the LCM that give a brake signal, but one also pulses with the turn signal, and the other seems to be slightly under-voltage, which results in my Prodigy2 controller display spazzing out. Despite the display issues, the controller DOES work, so I put up with it for a couple years. Supposedly, you can find a clean source at the high-mounted brake light on the rear hatch. I never bothered, so I can't verify.

AM.

I will see if I can find what wire I have, I have no problems with mine after install. Keep in mind that you need to use a PWM trailer light module as well, are you doing this or did you tap directly into the tail lights for the right/left/tail signals?

edit; 15 pin black connector on LCM Pin 10 "high mounted center stop light"
blue with yellow trace.

This is what it is for my 03 4.4, I would assume the other model years are the same but I dont know

[Attacking Mid]

Originally Posted by Lowblock

I will see if I can find what wire I have, I have no problems with mine after install. Keep in mind that you need to use a PWM trailer light module as well, are you doing this or did you tap directly into the tail lights for the right/left/tail signals?

I had the BMW harness installed. Only the brake controller wiring was separate, as BMW didn't provide for that in their harness.

I have recently removed my hitch and sold it as I'm preparing to sell my E53. I really liked my E53, but the M54 just didn't have enough power to tow my camper trailer. I now have an E70 35d that pulls it with much more authority, and the trailer wiring harness in it DOES include provisions for the brake controller.

If only the actual hitch was as beefy and well-engineered as the E53 hitch!

AM.