Factory "Electrical trailer tow" wires 2004 F150
 

Just bought a used 2004 Ford F150 Lariat with 134,000 miles on it. It is equipped with the factory towing package. It was literally bought by and driven by a rich old lady who never towed anything with it. I opened the glove box and found still in the plastic package a set of instructions, a relay and wires with one plug in on the end. According to the instructions I am suppose to plug the relay in, plug the wires in to the open connector under the dash and splice in the brake controller. I thought the whole idea was a little crappy of Ford. Paying for a tow package and they hand you a bag of parts and say, "here you go"! I know things have changed alot since 2004. Do I still need to plug in the relay with one of the new "plug and play" brake controllers? It sounds like the relay powers the batteries on the RV trailer. I know on my 2002 I bought a time delayed plug and play controller and it powered the batteries BUT was not very smooth. I am looking at a Proportional Brake Controller now. Thanks