Notices
1961 - 1966 F-100 & Larger F-Series Trucks Discuss the Slick Sixties Ford Truck

Wiring Gurus please...

Thread Tools
 
Search this Thread
 
Old Apr 16, 2018 | 03:22 PM
  #1  
resonateur's Avatar
resonateur
Thread Starter
|
Fleet Mechanic
Joined: Jan 2014
Posts: 1,946
Likes: 118
Wiring Gurus please...

Working on salvaging my '66 main loom and fortunately I have a 65 loom to rob from and splice in the damaged sections. I'm trying to identify every connection and I can't seem to find this one in the wiring diagrams. There's two sections to the main under dash loom, one of which exits the firewall into the engine compartment. Through the firewall there's a green/w/red tracer wire that is cut and goes nowhere in the engine compartment. I'm assuming it was for some accessory that this truck never had. It goes to this double male/female plug under the dash (shown). The female end of both looms I have was not connected to anything. The male end goes to a blue/w/


red tracer wire just over the light switch connector, which is the indicator light circuit. Can I assume, that I can eliminate this wire as it seems to have no purpose? As always, I appreciate the expertise on this forum, which has gotten me this close to completing my project!!
 
Reply
Old Apr 16, 2018 | 09:30 PM
  #2  
gcooter's Avatar
gcooter
Mountain Pass
10 Year Member
Photogenic
Photoriffic
Liked
Joined: Jan 2015
Posts: 127
Likes: 7
From: South of Madison WI.


I don't see a green wire with the red tracer in this diagram. I changed alternator types and on the newer alternators the green wire with the red tracer runs from the internal regulator on the alternator to the idiot light or amp gauge in the dash.
 
Reply
Old Apr 17, 2018 | 04:17 AM
  #3  
Crop Duster's Avatar
Crop Duster
Logistics Pro
Veteran: Air Force
10 Year Member
Joined: May 2015
Posts: 4,474
Likes: 974
From: Tri Cities, TN
Club FTE Silver Member

The Green/Red in the oil/alt harness,( C5TA-10A665-C ) was cut off in both of the harness's I took apart. I suspect as you do that it was for something in a much larger truck. I removed it when I re-taped the harness.
I do not see this red tracer wire you speak of but if it the red/yellow tracer under your thumb, it's for the dimmer switch and if it is the one with blue tape on it, that one I believe is for rear lights, which I assumed to be marker lights on a camper. It's useful for other things keep it.
 
Reply
Old Apr 17, 2018 | 04:22 AM
  #4  
David7.3's Avatar
David7.3
Postmaster
Joined: Jun 2014
Posts: 3,206
Likes: 3
From: Oakhust NJ Jersey Shore
You can use it for , aux. wiring up to running lights or cab lights, it would be a nice addition put since it doesnt dim, I wouldnt use it for gauges or something of that nature.
 
Reply
Old Apr 17, 2018 | 09:50 AM
  #5  
resonateur's Avatar
resonateur
Thread Starter
|
Fleet Mechanic
Joined: Jan 2014
Posts: 1,946
Likes: 118
All:
Thanks for your help!! Yes, I was going to keep the indicator light wire for the purposes such as you suggested. The red tracer is really hard to see as the green wire has become so dark with age. The dimmer switch wiring is intact. As CropDuster suggested, and I assumed, the "wire to nowhere" is going away.
Thanks again....
 
Reply
Old Apr 17, 2018 | 02:59 PM
  #6  
Fords & Whalers's Avatar
Fords & Whalers
Mountain Pass
Joined: Oct 2010
Posts: 155
Likes: 2
From: Marin County CA
I recently purchased the same wiring harness (C5TA-10A665-C) for the optional oil/alt gauges I installed on my 1965 F100 dash panel, and the green/red wire was also nipped off on the engine side of the rubber firewall grommet . Quick favor, can you send a photo (or description) of the location of the hole for the rubber firewall grommet? I have to drill this in my firewall since I'm adding the gauges and wiring harness myself and want to make sure it's in the correct location.
 
Reply
Old Apr 17, 2018 | 10:35 PM
  #7  
resonateur's Avatar
resonateur
Thread Starter
|
Fleet Mechanic
Joined: Jan 2014
Posts: 1,946
Likes: 118
Fords...here you go. The hole is .85" inside diameter, with the edge rolled in towards the inside of the firewall.
 
Reply
Old Apr 18, 2018 | 12:26 PM
  #8  
Fords & Whalers's Avatar
Fords & Whalers
Mountain Pass
Joined: Oct 2010
Posts: 155
Likes: 2
From: Marin County CA
Excellent photo and description, thank you!
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Ways Ford is LOSING to the Competition

 Joe Kucinski
story-1

Top 6 Best Deals Available on New Fords & Lincolns Right Now

 Brett Foote
story-2

This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

 Verdad Gallardo
story-3

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-4

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-5

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-6

Every 2026 Ford Engine Explained

 Brett Foote
story-7

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-8

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-9

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Ben Samways
1973 - 1979 F-100 & Larger F-Series Trucks
17
Sep 1, 2017 11:07 AM
1930 Dodge
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
14
Mar 14, 2016 09:54 AM
alpha/omega
Offroad & 4x4
11
Jun 6, 2011 08:35 AM
txfour
1973 - 1979 F-100 & Larger F-Series Trucks
11
May 20, 2009 06:56 PM
78blackf150
1973 - 1979 F-100 & Larger F-Series Trucks
3
Nov 22, 2007 03:26 PM




All times are GMT -5. The time now is 08:12 AM.

story-0
10 Ways Ford is LOSING to the Competition

Slideshow: 10 ways Ford is losing to the competition

By Joe Kucinski | 2026-06-15 09:52:01


VIEW MORE
story-1
Top 6 Best Deals Available on New Fords & Lincolns Right Now

Some great targets in today's expensive world.

By Brett Foote | 2026-06-15 09:35:19


VIEW MORE
story-2
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-3
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-4
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-5
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-6
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-7
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-8
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-9
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE