Trailer Wiring?

[JGrefenstette]

on my 93 W250, i dont have the tow package. and its never towed anything. ive loaded down the bed, but never pulled trailer. i plan on doing some towing however, and will want to be able to tow a big enough trailer to put other trucks on. (not a gooseneck, ill just be using a drophitch off the rear. ) with that said ill be wanting to have more than just a little 4 pin light wireing. id like to wire it for trailer brakes. now im new to the whole towing deal. i have towed a fair amount with other trucks, but never dealt with wiring anything. just hooked it all up to the trailer and go. so here my questions:



1. were do i run the wires to on the truck? how/and where do i tie into for the brakes? i assume ill need a brake controller too?



2. do the wires for the lights hook into the tail light wires out back, or go somewhere else along with the brake wires?



thanks yall

 

[dd76522]

ah my favorite nightmare! seems every truck i've ever owned has been hacked in this area normally what i do is install a standard 4 pin flat which it sounds like you allready have? then on the back side of which ever larger connector you use be it 6 or 7 pin install a trailer side 4pin and connect the 2 4 pins which is nice if you ever need the 4 pin and don't have an adapter handy the other two wires for a 6 pin one is an auxillary power which you can connect to the battery thru a fuse or leave off unless you need it then the trailer brakes will depend on the controller which you'll have to buy i can't for the life of me remember what the 7th pin is a 7 pin connector though lemme know if you need a diagram and i can email one to you

dave

 

[JGrefenstette]

well the thing is i dont have ANY wiring of any kind for a trailer. nothing at all.



let me see if i understand. i need a power sorce to the harness on the rear bumper, probly connected to the ingnition switch in some way? and another wire going from the harness to a brake controller? and then hook ups for the lights?

 

[cojhl2]

Just a quick interjection here then I'll let dd7652 continue with his help.



In order to plumb the light wiring in you go get a "T" Connector that fits the pickup model. That brings out all the light wiring.



For the brakes you have no option, you must go thru a brake controller of some kind and that will require a separate feed back to the trailer connection.



Good Luck,, do a good job you will never be sorry for it. Trailer wiring is the most screwed up mess when not done correctly.

 

[WJones]

get a hoppy 7pin connector with the 4 pin on the side so you have the option for either. I doubt your gonna find a Tee so your going to have to splice the harness.



youll need a wire for electric brakes (unless you use surge) and a wire to charge the trailer battery (switched or isolated to prevent the trailer from sapping the battery)



the 7th pin is the aux, usually backup lights on the trailer.



i added a second +12v line going to the back to feed the relays that isolate the trailer wiring from the vehicle wiring.

 

[dd76522]

with no wiring at all imho the easiest way to do it would be check for a t at a parts store or here online if theres not one available if you remove both taillights, turn on the parking lights and 4ways you should have three wires going into the upper bulb on each side one is the ground and should be easy to figure out use a test light to figure out which of the remaining 2 are which you only need to connect the brown wire from the trailer harness to one side of the truck since it's the parking lights and then the wires that make the test light blink are your turn signals that'd be the yellow and green then white to ground and you're good and it'd definetly be a good idea to soder and shrink wrap if you can those elcheapo scotchlock splices are junk the give you grief if you use them! good luck!

 

[KOG]

http://www.tekonsha.com/Wire/PDF/Ceq-Wiring-pg31-38-2006f.pdf

This will get you started. Run 12ga wire from the battery to your brake controller and to your 12V battery charging lead (breakaway kit on trailer). Use 20 amp autoreset breakers on those lines. If you use LED lights on the trailer you won't need relays for tail/brake/turn lines. You will have to have clearance lights on cab if your trailer is over 80" wide - and it will be.

 

[cojhl2]

Hmmm,,, maybe they don't make T connectors anymore. I bought one from

https://terminalsupplyco.com/products/prod_catalog_pdf.asp a few years ago.



Neverthless they are a source of many parts for which you are doing.

 

[rumblefish]

Valley and Hoppy both still make the T- connectors. I just bought one a month or so ago. I'll see if I can dig up the part number.

 

[rumblefish]

Alright, I'll go you guys one better. I loked in the catalogs at work tonight and this is what I came up with.



Valley: 32105

Hoppy: 42105



This part number fits 86-93 D & W series, Ramcharger, 94 Ram, an 87-02 Cab and Chassis



Alot of times the parts store could give a doo doo about our old trucks, but thrive on the newer stuff. Keep in mind that the 94 ONLY 2nd gen trucks use the same T connector according to my catalog. I know where I work, it did not list anything for the 93 or older in the computer, but it did for the 94. Go figure.

 

[JDancoe]

J-Checker Auto, WalMart and I'm sure NAPA and other auto parts or RV supply stores should have the Hopkins "Hoppy" Plug-In Simple trailer wire kits. The numbers Rumblefish offered is ,I believe for the Four-pin flat connector, but they should cross-reference. I'd suggest asking for the 7-pin RV connector, possibly with the 4-pin siamesed on the side. It should come in a kit, with tee adapter, wire, receptacle, mounting bracket, etc. AND INSTRUCTIONS! Otherwise, if you have only the 7-pin, you can get a variety of adapter plugs 7 to 6 pin, 7 to 4 pin etc. that just plug in. Jack Dancoe

 

[JDancoe]

J - I forgot to mention the brake controller. That is only necessary if the trailer(s) you are towing have electric brakes. If the trailer has surge (hydraulic) brakes, like U-Haul or most boat trailers, that's not required. Brake controllers should be available from the same source as the wiring kits. I've had god luck with Tekonsha units, but there are several good ones out there. Again, they come in kit form, with instructions. Jack Dancoe

 

[cojhl2]

Alright, I'll go you guys one better. I loked in the catalogs at work tonight and this is what I came up with.



Valley: 32105

Hoppy: 42105

Oboy,, looks like another source for stuff we need. How does one get connected to these guys? Who are they?



Thank you in advance for the info.

 

[BHiggins]

Hooking up a "T" connector for the lights is one thing, but if you're not 110 percent sure about wiring the brakes, I recommend having someone (a professional) do it. I'm all for "do it yourself", but you don't want to mess around when it comes to stopping a heavy trailer. Just my two cents.

 

[rumblefish]

Any auto parts store should be able to get them. I work at O'Reillys. I used to work at Advance, and they carried them as well. Indeed, these are only for a 4 pin connector on the trailer side, but it will then plug into the 4/7 pin connector side by side deal that JDancoe spoke of.

 

[JGrefenstette]

thanks yall, this is good info that will really get me going on this project. as i get into it ill have many more questions im sure. ill keep yall up dated.

 

[JGrefenstette]

oh and along with what you said about cab lights KOG..... i took care of that problem a few weeks back

I have proof in the photo gallery