Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

Trailer Light Harness

Thread Tools
 
Search this Thread
 
Old May 23, 2011 | 02:00 PM
  #1  
Justin's Green Truck's Avatar
Justin's Green Truck
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 379
Likes: 0
Trailer Light Harness

Hi,
I have a 1977 F-150 Custom with 351m and 4x4.
I bought a new trailer this weekend to pull my boat and it has the 5 pin trailer electrical harness. Now the truck only has a 4 pin. The extra one on the trailer, from what i understand is to allow the trailer to be reversed since it has disk trailer brakes. I imagine there is an electrical solenoid on the trailer that keeps the brakes from applying when you go to back up.
Now my question is: What is needed to make this work with my truck? Is there an adapter for the pigtail or do I need to connect that extra wire on the trailer to my reverse lights on the truck somehow? Thanks for any help.
 
Reply
Old May 23, 2011 | 02:21 PM
  #2  
Justin's Green Truck's Avatar
Justin's Green Truck
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 379
Likes: 0
Looks like I need to wire in a 5 pin harness to the truck and connect the extra one to the reverse lights. Is this correct?
 
Reply
Old May 23, 2011 | 03:38 PM
  #3  
78 PEB's Avatar
78 PEB
Cargo Master
Joined: Oct 2010
Posts: 2,674
Likes: 16
From: Ideeho
Never seen anything like youre describing................ Normally, trailer wiring consists of the following circuits:
Left turn / Brake light
Right turn / Brake light
Tail lights
Trailer brake feed
Ground
B + Hot wire for interior lights
Possibly a switched hot lead for charging a battery on the trailer/ or for reverse lights on the trailer.
A lot of times noone runs the ground wire, thinking it will ground thru the ball, but I highly reccomend utilizing the ground. It prevents a lot of problems
 
Reply
Old May 23, 2011 | 11:35 PM
  #4  
EJ AZ's Avatar
EJ AZ
New User
Joined: Aug 2009
Posts: 22
Likes: 0
You are absoultely right. You need to get a 5 flat plug for the truck hook up all the colors just like your current 4 flat and run the extra wire to the reverse. The nice thing is that your other trailers that use the 4 flat will usually plug right in to the 5.
 
Reply
Old May 24, 2011 | 10:24 AM
  #5  
Justin's Green Truck's Avatar
Justin's Green Truck
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 379
Likes: 0
Thanks for the help. I got it fixed last night. Theres an adapter that they sell at parts stores for this. You just plug it in and run the extra wire to your reverse light circuit on the vehicle.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
inboardfan
All Things Towing
11
Nov 19, 2015 09:16 PM
Tifford
Electrical Systems/Wiring
2
Sep 14, 2013 05:54 PM
CobraGT40
1999 - 2016 Super Duty
5
Aug 26, 2013 09:17 AM
johnEboy
Explorer, Sport Trac, Mountaineer & Aviator
4
Apr 20, 2008 12:34 PM
RussellF
All Things Towing
22
Apr 1, 2007 10:23 PM




All times are GMT -5. The time now is 11:21 PM.

story-0
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-1
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-2
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-3
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-4
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-5
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-6
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE
story-7
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!

Slideshow: Ranking the 5 things owners love about their Super Duty and 5 things they don't

By Joe Kucinski | 2026-04-29 16:36:49


VIEW MORE
story-8
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!

Slideshow: Ranking all 12 Ford truck engines available in 2026.

By Michael S. Palmer | 2026-04-22 13:32:20


VIEW MORE
story-9
The Best F-150 Deal of Every Trim Level (XL through Raptor)

Slideshow: The best Ford F-150 deal for every trim level (XL through Raptor)

By Joe Kucinski | 2026-04-21 15:59:01


VIEW MORE