Where do I connect the trailer brake controler red wire. Instructions say to connect to the brake light switch but there is no wire at switch that is powered when pedal is pressed. I have been told that it connects to the BCM but I don't know where the BCM is?

The brake switch at the pedal does have six wires, but none go to the multifunction switch (on the steering column). The white wire with tan tracer goes to the combination flasher to be integrated with the turn signals/hazard lights. The combination flasher is under the dash next to the steering column and has a sixteen pin connector (ten of which have wires).

Your truck may have had the factory trailer tow package, but that did not come with a wiring connector in that year. There should be a wire harness under the rear of the truck near the center of the bumper with 7 wires of the following colors/characteristics -

Red/Orange - +12V Battery (Thick Wire) From fuse #8 (40A)
Black/Orange - Tail Markers (Thick Wire)
Light Blue - Trailer Brakes (Thick Wire)
Violet/Black - Backup Lights (Thin Wire)
Dark Green/Red - Left Stop/Turn - (Thin Wire)
Brown/Red - Right Stop/Turn - (Thin Wire)
Black - Ground - (Thick Wire)



Under the dash, the brake controller wiring should be -

Red/Orange - +12V Battery (Thick Wire) From fuse #8 (40A)
Black/Orange - Ground - (Thick Wire)
Light Blue - Trailer Brakes (Thick Wire)
White/Tan - Brake Light sense - (Thin Wire)

Hope this helps.

Hello Carol, The 7 way is for use with a brake controller and/or a trailer that has electric brakes. The 4 way flat is a basic trailer plug connector.
Connect as follows:
Green wire- Connects to the vehicles right turn wire harness & provides brake light and right turn signal on trailer.

Yellow wire- Connects to vehicles left turn wire & powers brake light & Left turn signal on trailer

White wire- Ground

Brown Wire- Tail/ marker/ license plate lights

The Blue, Red & Purple wires on the 7 way will not be used on the adapter, those are for brakes.

I hope this information is helpful.

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Trailer Wiring Diagrams 4 Way Systems

4 way flat molded connectors allow basic hookup for three lighting functions; right turn signal / stop light (green), left turn signal / stop light (yellow), taillight / license / side marker (brown) and a ground (white).

4 way tow vehicle side.
4 way trailer side.
5 Way Systems

Same as 4 way system listed above but adds a extra blue wire for brake signal or auxiliary power. Used on pop up camper trailers or utility / boat trailers.
5 way tow vehicle side.
5 way trailer side.
6 Way System, Rectangle Plug 3/4 inch by 1 inch 6 way rectangle connectors right turn signal (green), left turn signal (yellow), taillight (brown), ground (white). The red and blue wire can be used for brake control or auxiliary. Use on a small motorcycle trailer, snowmobile trailer or utility trailer. Can also be used as custom wiring on trailers with 3 light/wire systems. See "Tow Vehicle Taillight Wiring" below.
6 way tow vehicle side.
6 way trailer side.
6 Way Systems, Round Plug

Round 1 1/4" diameter metal connector allows 1 or 2 additional wiring and lighting functions such as back up lights, auxiliary 12v power or electric brakes. Note: The black (sometimes red) 12v and blue electric brakes wire may need to be reversed to suit the trailer. Check with a test light or VOM. Uses: horse trailer, travel trailers, landscaping trailer, car trailer, etc.

6 way tow vehicle side.
6 way trailer side.
7 Way Systems

Round 2" diameter connector allows additional pin for auxiliary 12 volt power or backup lights. Uses: heavy duty landscaping trailer, car trailer, boat trailers, horse trailer, travel trailer, construction trailer, etc. Check with a test light or VOM.

7 way RV flat blade tow vehicle side.
7 way RV flat blade trailer side.

Hi. There is a grey plug with 6 wires right behind your OBDII diagnostic port on the lower dash board above your accelerator pedal.

The color of the wires on the plug are blue, green, red, white and brown. The wires are as follows:
Blue....electric trailer brake feed
Green....brake pedal switch
Red...12v postitive...always hot
White....ground
Brown....interior vehicle illumination (not used)

The factory wire harness that you will need to attach your brake controller will plug right into this plug. The factory wires are colored the same as above.

After-market and brake conroller wires are colored as follows:
Blue....electric trailer brake feed
Red.....brake pedal switch
White....ground
Black....12v positive

1. connect the red wire to the stop lamp switch lead on the brake control. Connect the other end of red wire to the stop lamp switch in the vehicle using the splice connector

2. connect the blue wire to the trailer brake lead on the brake control. Route the other end of the blue wire to the trailer connector at the back of the vehicle.

3. connect the white wire to the ground lead on the brake control. Route the other end of the white
wire to the vehicle’s battery. Use the ring connector to connect the white wire to the battery’s negative terminal.

4. connect the black wire to the power lead on the brake control. Route the other end of the black wire to the vehicle’s battery. Use the fuse assembly to connect the black wire to the battery’s positive terminal.

Trailer end; Red=Brake
Brown=Running lights
Yellow=Left
Green=Right
White=Ground
You will need a turn and brake signal box IF, you have different bulbs for brake and turn lamps. If the brake and turn bulbs are one(red)lens than no box will be required. Thanks, Dana

a brake controller has 4 wires on it, Black, white, blue,red.

Black is positive battery 12 volts connect to 30 amp circuit breaker to the battery

White goes to good solid ground

red connects to white wire from the brake switch

blue wire connects to 7 way trailer connector at rear of truck. If the truck has trailer package you will find the blue wire and red wires under brake booster taped to the harness you can connect your blue brake control wire to that blue wire. At the rear of the truck the other end of the blue wire will be taped to a harness under the rear of the truck. you will have to now connect the blue wire to the blue input on your 7 way connector

I belive it would be the wire that actually sends the control signal to the controller?...correct? well the if so you would need to tap into the wire casing with a test light to see which wire is lighting the test light when the brake pedal is depressed good luck

Truck Brake control

Red/Black stripe Black

Blue Blue

Lt. Blue/white stripe Red

White White

Orange Not used