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Mttlh4's avatar
Mttlh4
Explorer
Mar 07, 2016

Help with TV trailer wiring harness?

My wife and I just purchased a 2004 Suburban 2500 for our TV. Unfortunately, it is not equipped with the factory tow package. This not a problem as I don't mind installing the necessary equipment. Which brings me to my query, I would like to find a plug and play wiring harness to make installation a little easier, but the product descriptions that I've found are very generic and don't say exactly what is included with the kit or if additional pieces are needed when incorporating a brake controller?
I will add that we have not taken delivery of the burb yet, but when checking the vehicle, I saw a round plug tied to the frame under the bumper. Could this be the factory harness and all I have to do is connect the 7way plug to it?
If anybody knows which kit I should be looking for I would appreciate it. I'm not opposed to splicing in a universal wiring harness, but a plug in would be preferred.
Tow Vehicles
  • Mttlh4's avatar
    Mttlh4
    Explorer
    May 26, 2016
    Installation was simpler than I expected.
    Once we took delivery of the suburban and checked the owners manual, I found that the suburban is equipped with a basic tow package which appears to be a standard item. Essentially it includes the wiring from the fuse box to the rear of the vehicle.
    All I needed to do was install an OEM type 7pin RV plug and the correct fuse for the brake controller and it was all set.
    From what i could gather in the owners manual, all 2004 suburbans are equipped with at minimum the basic tow package , as mine was. The optional heavy duty tow package adds the 2" receiver hitch and 7 pin plug.
  • Fast_Mopar's avatar
    Fast_Mopar
    Explorer
    Mar 08, 2016
    Mttlh4 wrote:
    What I was really looking for is if anyone could tell me the likelihood that GM has the wiring pre installed from the fuse box to the back of the vehicle or if I can expect to install that myself.


    I don't know the answer to your question. But, if you do not have the harness, my recommendation is to buy a factory GM harness from the dealer and do not use the "plug and play" kits at the auto parts store. My 2004 Ford Freestar van does not have the factory tow package. I initially bought a "plug and play" kit from an auto parts store that connected to both tail lights. It worked for a little while, then I started having many problems. I eventually went to the Ford dealer and purchased the correct harness kit which also came with a couple of fuses for the factory fuse box, and I wired up a round 7-way plug, and that has worked great for 12 years.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Mar 08, 2016
    Mttlh4 wrote:
    Thank you for the advice.
    I have the non-electrical items needed pretty much under control, just waiting till we bring the vehicle home to start making those purchases.
    What I was really looking for is if anyone could tell me the likelihood that GM has the wiring pre installed from the fuse box to the back of the vehicle or if I can expect to install that myself. I am familiar with electrical circuits, I'm just looking to get the parts I need in one purchase without having extra unused pieces.


    No 'factory tow package' then no wiring harness.

    What previous owners have done??

    That is something YOU would have to see for yourself
  • Mttlh4's avatar
    Mttlh4
    Explorer
    Mar 08, 2016
    Thank you for the advice.
    I have the non-electrical items needed pretty much under control, just waiting till we bring the vehicle home to start making those purchases.
    What I was really looking for is if anyone could tell me the likelihood that GM has the wiring pre installed from the fuse box to the back of the vehicle or if I can expect to install that myself. I am familiar with electrical circuits, I'm just looking to get the parts I need in one purchase without having extra unused pieces.
  • wgriswold's avatar
    wgriswold
    Explorer
    Mar 07, 2016
    U-Haul had a plug and play 7 pin plug for my 1999 Suburban and probably has one for yours. Prodigy also has a plug and play brake controller wiring harness.
  • petrel's avatar
    petrel
    Explorer
    Mar 07, 2016
    another vote for etrailer.com. They can probably tell you what you need.
  • RoyB's avatar
    RoyB
    Explorer II
    Mar 07, 2016
    My 2004 F150 Truck had this trailer hookup under the rear bumper... It has two doors one for 4-way connections and the other door for 7-way connection.

    I would think most truck type vehicles would come woth this as a minimun...



    Found this 2007 Expedition Tow Package setup (google on-line) with the 4-way on one side and the 7-way on the other side of the hitch. Hopefully the older Suburbans do the same thing...



    I found ETRAILER.COM was a great place on-line for all things truck/trailer towing... Lots of diagrams and how-to videos

    Roy Ken
  • Tvov's avatar
    Tvov
    Explorer II
    Mar 07, 2016
    A local auto parts store, hopefully with counter help who knows what you are asking, may have what you need. Years ago I added a trailer plug to one of my trucks and my local NAPA store had the proper "plug and play" connectors for my truck.

    An aftermarket brake controller may need to have wiring run from the dashboard back to the trailer plug. If you don't want to do it (it is not really that hard once you see what is done), a local mechanic will probably be able to do it for you... or a truck dealer if you want.
  • LarryJM's avatar
    LarryJM
    Explorer II
    Mar 07, 2016
    As mentioned you will not only need to install a 7 wire trailer plug, but figure out how to hook up your brake controller. Then there are the non electrical "tow package" items such as maybe larger radiator for HD cooling along with an extra transmission cooler and maybe even an oil cooler which might all be dependent on the particular make, model, and year of your TV. One potential $$$$ one might be the rear gearing to get you to the correct tow weight rating. Vehicle "tow packages" are generally more than just the electrical and even at times have different levels such as "standard" or "heavy duty" tow pkgs.

    Thus to "upfit" a non tow pkg vehicle to one that has all the items in the factory pkg can get a tad bit pricey and might not be the simple "plug and play" that you might be envisioning.

    Larry
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Mar 07, 2016
    If you have the owners manual look for towing section or fuse section.

    You will need to identify the fuses needed to be installed for trailer circuits.

    Then look under dash behind e-brake for connector.....that is what brake controller pigtail harness would plug into
    Then you would need 7 pin wiring harness from fuse box/brake controller to rear of Suburban (7 pin provides running lights, R & L turn/stop lights, backup lights, ground, trailer brake wire (from controller output) and trailer charge line)

    That round plug MAY be a 7 pin or even a 6 pin (no charge line to trailer battery)

    In addition to wiring harness, brake controller, brake controller wiring pigtail, a good hitch receiver........you would benefit from a tranny cooler and higher volume air intake filter along with 3:73 gearing

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