"Standard" Wire colors to the controller:
Black, Battery Positive to controller
White, Negative Ground for Controller
Blue, Brake feed from controller to Trailer plug at back of truck
Red, tap into truck Brake light switch signal to tell controller to apply brakes
Remember, the above colors are just a GUIDE. your colors may be different, read the instructions! I have seen many factory harnesses that have a extra wire for dash lights (usually brown). Most controllers do not have "dash lights" so don't hook that wire up.
Installing a brake control unit isn't very difficult. This task is made even easier if your tow vehicle is a late model and comes with a 7 Way Connector as part of the towing package.
In this case, installation is as simple as mounting the brake controller in a convenient, easy to reach place, usually under the dash, just above your right leg and connecting the wires from the brake control to the wiring harness and then plugging the harness into the harness located under the dash.
Most newer vehicles equipped with towing packages are now
providing a wiring harness which looks similar the ones in the
picture below depending on the make of your vehicle:
Dodge vehicles have an independent and movable wiring harness. On some dodge vehicles, the harness is found loosely stuffed under the dash above the driver's right leg. And on others, it can be found attached to a module above the driver's left leg. The harness connector is often blue as shown in the picture below. You must have the factory plug harness to plug in (I sell these, if you need one, hint, hint)
Then it is just a matter of connecting the harness up to your brake controller, according to the wires colors above using butt connectors, and then plug it in. Mount the controller where your want it. I prefer to have it on the right side of the steering wheel, within reach of my right hand. Just screw the bracket right into the plastic dash panel (I know, it hurts!)
Now, under the hood, is the fuse box. You MAY need to
install the fuse and or relay for your trailer brakes. You will
have to look in you owners manual to find the fuse size and
location, and any relay you may need to install. Sorry, they are
all different. Often your truck came with a extra fuse. I have
found them to often be the large square type fuse, and is it
labeled the "trailer" on the underside of the fuse box lid.
In order for this to work, you must have the factory tow package.
I can not promise this is good for all Dodges. If you do not
have the factory tow package, you may still have the plug under
the dash. If so, you may have to run a wire to the back of the
truck, but you may at least have the brake light signal wire. If
you have nothing, or this is a older truck, you will have to run
the blue wire from the controller all the way to the back up the
truck, and connect to the blue terminal on the trailer plug. You
will also have to locate the brake light switch, and find the wire
that is hot when the brake lights come one (be careful if you have
ABS, not to get the wrong wire, it will mess up the ABS!). In
addition, you must provide the controller with fused battery + and