Pretty easy. If all you have is the 4 pin from the factory and get that kit I linked to, you'll just have to drill a hole in the frame and solder a wire onto the driver-side tail light harness, then just run the wire up front, zip tying along the way. Took me maybe 40 min to do.

 

Thanks Mozingod. That was the info that I needed. One more thing. Does it go in the stock location?

 

FYI......... I just bought my '04 Ram a couple months ago to pull my tent trailer. I installed a hidden hitch and 7-pin connector. The 7-pin adapts to the 4-pin the truck came with. I have the "tow/haul" button, but I'm guessing no "towing package" because there is no connector under the dash (no matter how many times the Dodge parts guy tells me there is) to mate a trailer brake controller adapter (sold to me by the insistent Dodge parts guy) to.

So I'm manually installing by tapping brake, hot, grnd, etc.

Just FYI in case some Dodge parts guy tells you all you need to hook up a brake controller is a little blue adapter with four wires hanging out of it.

 

I jus put a Prodigy contoller on my brother in laws 1500 and could not find any sorce for brake light hookup. This p/u was NOT delivered with the Tow Package, consequently no wiring plug under the dash. I used the hot when brakes are applied wire coming out of the brake light switch. I removed the brake light switch to tap into the wiring when I found printed on top of the switch "DO NOT REINSTALL". I did and the brake lights stay on when the key is turned on and the ABS lgiht on the dash was on. Since the switch is basically "ON" or "APPLIED" the crusie would not work also. I am now looking for a new brake light switch. Anybody help me on a hidden blue wire under the dash. I heard a rumor it exists, but is very difficult to locate. HELP!

 

I have an 05 ST HEMI and installed a hitch and brake controller. There is an available plug which
I bought that plugs into the factory plug under the dash, but on my truck the output for the brakes,
and the stop lamp wire only leave the cab to stop at a connector full of wires under the truck. ( drivers
side right behinde the front wheel well) I then had to tap those two wires and run them back to the
seven pin plug.

Definately a pain in the butt, but using the factory plug saved a few steps.

 

I have put a few electric brake controllers in for other people on the Dodge truck and have never seen one from the 03 model, forward that did not have the receptacle under the dash for the controller. This is true regardless of whether it came with the towing package or not.

The only wiring that has to be completed is the wire to the battery, (do use an inline fuse at the batteryend, please), and the blue wire has to be extended from the connector under the truck, behind the right front wheel well. It is necessary only to extend the wire coming from the connector that the blue wire feeds into, this is the electric brake wire, the stop lights are already back there in the 4-pin connector that comes on the truck. The kit that the Dodge dealers sell for converting the 4-pin connector to the seven pin have always worked out great for me, and it also contains good instructions.

The only problem you may encounter is finding the proper harness for the controller, that mates into the under dash receptacle. I, personally, wouldn't use any other controller than the Prodigy, and I do a lot of trailering and initially used other brands. The harness for the prodigy is easy to come by from several sources on the internet.

 

Im no expert at this but the way we normally do this sort of thing in my familly is to just wire up a new external plug. We'd find a 5pin or 7 pin or whatever we need to fit the vehicle and do the same with what we need for our trailers and splce the wires for each and join them together. Its worked with all our vehicles and trailers so far and beats the hell out of trying to rewire your vehicle.

On a side note though I strongly suggest that if you are rewiring your truck you put some type of in-line fuse in about 10-12" after your battery. On the slim chance that the live wire were to get worn down or melt and start shorting out this will save your battery and if the undercaridge of your truck is oily or greasy or has any type of gas leak that you dont know of it could also save you from fires as well if it ever started to arch. Its one extra step but it will save you in the long run.