I Have NO trailer wiring harness. I am in need of a 7 way, with brake controller. I plan to buy a 4 way, simple factory plug into brake light, style connector. Couple that with a universal 4 way - 7way adapter. I DO have a factory brake controller plug under dash behind the e-brake area. Most instructions point to wiring the B+ and brake control wires directly to the controller and battery respectively, adding 40amp fuse for B+. I have found the factory blue controller wire and the B+ wire, already connected to a 40A fuse. Both wires are terminated at the 2 wire harnesses located behind the drivers side fender well. One harness has the blue wire on engine side of plug with no out wire. The other harness has a red/yellow B+ with no out wire. I tested the B+ with and without the fuse to confirm. I did a continuity test from the blue wire (which I understand to be in the electric brake control)on the harness in cab to the harness behind the fender well.

 

I would like to run the 2 wires to the back of the truck to complete the 7-way connector utilizing the existing factory fuse electric brake wires. I have not found any posts utilizing this setup. Seeing if there any objections to my madness. I think it would be a cleaner and simpler install.

 

Would you ever consider using romex home wires? Its all nice and jacketed together

Edited November 11, 20195 yr by Irie808

I suppose romex would work.   I doubt you would have issues with the solid wire as that wire wouldn't really ever move / bend.

Edited November 11, 20195 yr by Me78569

Maybe I'm missing something...but  I used 7 wire trailer harness, I got it by the foot and no problems been since 05.  I was going to instal a 4 way, but i just picked up a 7 way to 4 way flat connector.  Link is just to give you spec,s.  But truck/trailer repair places you should be able to buy what you need by the foot. 

 

https://www.amazon.com/OPT7-Weatherproof-Blade-Adapter-Secure/dp/B01M18QTHY

 

https://www.amazon.com/Best-Connections-Trailer-Wiring-Harness/dp/B07NJ8PXWN/ref=asc_df_B07NJ8PXWN/?tag=hyprod-20&linkCode=df0&hvadid=317966907488&hvpos=1o2&hvnetw=g&hvrand=12462389089269044526&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9033337&hvtargid=pla-653486735214&psc=1

 

3 hours ago, 015point9 said:

Maybe I'm missing something...but  I used 7 wire trailer harness, I got it by the foot and no problems been since 05.  I was going to instal a 4 way, but i just picked up a 7 way to 4 way flat connector.  Link is just to give you spec,s.  But truck/trailer repair places you should be able to buy what you need by the foot. 

 

https://www.amazon.com/OPT7-Weatherproof-Blade-Adapter-Secure/dp/B01M18QTHY

 

https://www.amazon.com/Best-Connections-Trailer-Wiring-Harness/dp/B07NJ8PXWN/ref=asc_df_B07NJ8PXWN/?tag=hyprod-20&linkCode=df0&hvadid=317966907488&hvpos=1o2&hvnetw=g&hvrand=12462389089269044526&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9033337&hvtargid=pla-653486735214&psc=1

 

I guess the ease of the factory tail lights to give me a 4way is nice ( plug and play @ $20 or less) then all i need is 2 wires going towards cab. Question is if those wires at drivers fender well are viable for B+ and brake controller if anyone has used those before. It already has a 40A fuse wired at factory fuse box. As stated I have NO trailer harness at all at this point. Taking a spool of 7 wires and wiring everything from scratch sounds a bit more confusing to get the brake, running and blinker lights correct.

 

https://www.amazon.com/gp/product/B0002Q7C08/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

 

After re-looking at the linked item it doesn't mention brake lights in description, could be a miss on their part but it looks a tad different than this item by Curt. @ $29

 

https://www.amazon.com/55329-Vehicle-Side-Custom-Trailer-Harness/dp/B0009I5WV0/ref=pd_sbs_263_4/132-4241595-7712258?_encoding=UTF8&pd_rd_i=B0009I5WV0&pd_rd_r=2d052afb-16f0-4ca2-af16-c28a0dfbbaff&pd_rd_w=uwZBo&pd_rd_wg=odhmW&pf_rd_p=52b7592c-2dc9-4ac6-84d4-4bda6360045e&pf_rd_r=6RANY8ABSSK5Q81RFR0R&psc=1&refRID=6RANY8ABSSK5Q81RFR0R

 

 

 

 

Edited November 11, 20195 yr by Irie808

Are you speaking of an RV trailer?

Yeah you could put in what you linked to, nothing matter with that.   Myself we use to a lot of camping in remote areas.  So I put in a junction box (so that I could run a charge line to extra batteries in bed of pickup.  And I'm able to run a small water pump to refill water.  Also which ever brake controller you decide on will probably have directions that should help.  Etrailer.com linked below has tons of stuff.  What ever you do make your wiring so if you brake down somewhere someone else can tow your trailer to get it off the road or back home.  Unlike me. Thinking I would out smart thieves, i wired up my old 84 Ford wrong on purpose.  Didnt turn out to good when AAA tried to tow our trailer when we broke down.  

 

Such as linked below. 

 

https://www.etrailer.com/question-363.html

 

https://www.etrailer.com/Accessories-and-Parts/Pollak/PK52248.html?feed=npn&gclid=EAIaIQobChMIi_-D59Xh5QIVAtlkCh2S1gk6EAQYASABEgIu_fD_BwE

 

Edited November 11, 20195 yr by 015point9
Add info

This is actually a 14ft dump trailer I bought used. I already had to change the wiring to the plug provided by PO as the colors did not match the manual. Think I got that part straightened out. Etrailer has taught me tons over the past few days, so much resources there. Thats where i got the start of this idea. I'm not wiring a trailer, that's done...i think. I'm wiring my truck for the 7way. It became more of a Dodge question when I want to tap existing factory wires i guess. Thanks for the responses 015.9