Wiring Harness Headlight To Firewall 1966

CJ's Part Number: WHL3
MSRP: $97.85
CJ's Low Price:
1508112000 40022
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Wiring Harness Headlight To Firewall 1966
Wiring Harness Headlight To Firewall 1966 Wiring Harness Headlight To Firewall 1966 Wiring Harness Headlight To Firewall 1966 Wiring Harness Headlight To Firewall 1966 Wiring Harness Headlight To Firewall 1966

Product Description

Headlight to Firewall Wiring Harness for all 1966 Mustangs.

If you're restoring a vintage 1966 Mustang, then you probably already know just how frustrating and difficult it can be to trace faulty wiring. So make sure to pick up this Headlight to Firewall Wiring Harness to make your restoration project even easier!

Features & Benefits:
- Direct Fit Replacement
- Connects Headlight, Parking Lights, Horns, Voltage Regulator, Solenoid and Plugs into Alternator Harness
- Correct Color Wires
- Factory-Style Connectors
- Connects to the Firewall Near the Master Cylinder
- Runs Along the Driver Side Inner Fender Apron and Across the Radiator Support

This Headlight to Firewall Wiring Harness is a direct fit replacement. It connects your headlight, parking lights, horns, voltage regulator, solenoid and plugs into the alternator harness. It features the correct color wires as well as factory-style connectors. This harness connects to the firewall near the master cylinder and runs along the driver side inner fender apron and across the radiator support.

Chances are, your 1966 Mustang wiring is due for a replacement. Worn-out wiring can cause major, more costly issues later on. It’s best to replace your aged wiring now, especially if you’re adding new upgrades to your classic car. At CJ Pony Parts, you’ll find original wiring replacements, modifications, stellar upgrades and more!

Order a Headlight to Firewall Wiring Harness for your 1966 Mustang from CJ Pony Parts today!

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Installation Instructions


Difficulty: Moderate

Mustang Applications

This product will fit the following Mustang years:

Product Reviews

Write a review
Wiring Harness Headlight To Firewall 1966 is rated 4.5 out of 5 by 8.
Rated 4 out of 5 by from Good fit but plugs need mods I bought this harness in Feb 2017. The wiring fit very well. The problem I ran into was with the plugs. I was not able to get the firewall plug to engage. After much checking I discovered that there were small dimples in the sidewall of the female connectors (tube) which prevented the male plug from going in. I am sure this dimple is meant to engage in the male plug and keep it from coming loose, but it was too high and required WAY too much force to engage. I took a drill bit that was just big enough to remove this protrusion and ran it into all the female plugs, and this allowed the plugs to engage properly. Only a very tiny amount of metal was removed. The original female plugs did not have the dimple/protrusion. Otherwise, this harness was great.
Date published: 2017-03-23
Rated 5 out of 5 by from Excellent Step by Step Directions I installed this wiring harness because I put in a new alternator and it burned out the connection between the old harness and the old alternator harness. Removing the old and installing the new took about 5 hours and I wasn't hurrying. As an added bonus the headlights used to flicker but with the new alternator, voltage regulator, and this harness that problem was solved too.
Date published: 2016-08-15
Rated 5 out of 5 by from Really good product Hello, I have just received, in record time, my order for a 1966 headlight wiring harness. It is exactly what I needed. Thanks to all the team of CJ since France See you soon.
Date published: 2015-03-18
Rated 4 out of 5 by from Must be improved I was obliged to remake the insulation (clearly not perfect) and can't install the grommet of the right horn (grommet approximately 8 inches from the terminal); so I had to cut the wire, drill the grommet, put the wire into the grommet, soler the wire and do a correct insulation using heat shrink tubing.
Date published: 2016-03-28
Rated 5 out of 5 by from Nice Product - needs wiring diagram This is a high quality replacement for the factory harness. Connectors are great and length is perfect. However, it would be nice to include wiring instructions. Needed to scour internet and old service manuals to get the color coding correct.
Date published: 2017-07-14
Rated 3 out of 5 by from Easy to install Didn't get every thing i needed. Need to purchase wiring for the alternator. Was not included with this harness.
Date published: 2017-09-18
Rated 5 out of 5 by from Perfect fit This harness was perfect .my son and I installed it in 2 hrs
Date published: 2015-10-14
Rated 5 out of 5 by from Easy installation I have a 1966 Mustang Coupe. This installed easy and everything fit together great. The Two Main Disconnects pulled off easily. Because of the age of the car and several previous owners, when I got to the front right headlight, I thought I might need a special head light harness like the tail lights. This isn't the case, the harness plugs directly onto a standard three prong headlight. You will have to take of the front light panel (for screws) and the head light ring. There is sufficient openings to get the wires to feed in and get them attached to each other in the headlight areas. The bullet plugs were extremely tight however and using great care I got them together using pliers to grip them firmly as I slid them together. The hardest part about this harness was feeding the bottom wires under the radiator. Sticking my fingers in the left hole under the radiator channel, once I felt it with a finger tip, I stuck a needle nose pliers in the hole so I could grab it and pull it enough forward to get it with my finger tips. I was careful to lightly grip it with the pliers as to not damage the wiring insulation. You really should spend the extra money and also order the "engine gauge feed wire" harness that goes from the other main disconnect at the fire wall (left) to the Starter Relay, temp sensor, oil sensor and the coil as well as order the "alternator wiring" harness. These three all fit together perfectly. Otherwise, you will find yourself having to do some "do it yourself" modifications to the wires up front. The three wire harnesses took me about 2 hours 15 minutes to install, half of which time was in the dark using a flashlight. I'm glad I ordered the harnesses, I've found a lot of bad electrical work done over the years on this car and the wires are all brittle and breaking. If you need to find wiring harnesses. Google your car and they are easily found on line. I've found them extremely useful.
Date published: 2016-01-28
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Product Questions

Will this wiring harness also hook up to the GT fog lights I purchased?

Asked by: Mustang Rebuild
The fog light harness is separate, here is the link. http://www.cjponyparts.com/fog-light-wiring-kit-1966/p/WFWK2/
Answered by: rk cjpp
Date published: 2016-05-23

Hello. Is this an Alloy Metal Products harness? Or is it still unbranded? Thanks.

Asked by: lesterdkhd
This is an alloy metal products harness.
Answered by: rk cjpp
Date published: 2016-02-19

Does this harness include the plug for the voltage regulator and the alternator?? 

Asked by: rjc69
This includes the voltage regulator plug and the plug for the alternator harness, the alternator harness is WALT3A for a 6 cylinder and WALT3B for a 8 cylinder.
Answered by: rk cjpp
Date published: 2016-09-20

How do I receive the points you talk about? From what I have ordered in the past, I have not received any points. Thanks

Asked by: Bama1
You receive points on every order. However, points do expire, so if you don't redeem them in time, they disappear. You can see the amount of points you've accumulated by logging into your account from the RPM club page: https://www.cjponyparts.com/customer/account/rpmclub/. That page also shows when the next expiration date is.
Answered by: CJ Pony Parts
Date published: 2015-10-02

With this harness, would I still need the headlight power upgrade harness, or is that basically built into this harness?

Asked by: Sixtringfling
They're for two different purposes. This harness is a factory replacement for your front lights, while the headlight power upgrade harness is specifically for adding more powerful headlights.
Answered by: CJ Pony Parts
Date published: 2015-07-06

What brand makes this harness?

Asked by: 66Coupe
This is unbranded, so it could come to us from several different manufacturers.
Answered by: CJ Pony Parts
Date published: 2015-04-09

will this work for a GT?

Asked by: scottylou
It works for all 1966 Mustangs.
Answered by: CJ Pony Parts
Date published: 2015-05-14
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