American Autowire Complete Wiring Harness Classic Update Kit 1965-1966

American Autowire:
American Autowire Complete Wiring Harness Classic Update Kit 1965-1966 is rated 4.0 out of 5 by 14.
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  • Complete Wiring System
  • Gauge Cluster Easily Wired In
  • Complete Wiring For All Lights
  • All Required Hardware Supplied
MSRP $859.00
You save 10%

American Autowire Complete Wiring Harness Classic Update Kit for 1965-1966 Mustangs.

The Classic Update Series is a complete wiring system in a box, giving you everything you need to modernize your classic Mustang's wiring system. Allows for most aftermarket accessories such as: gauge packages, heat and air conditioning systems, power windows, etc.

American Autowire's 510125 Classic Update Kit's instrument cluster wiring is designed with a separate "cluster harness disconnect" system for easy service and assembly. The best aspect of the disconnect system is that any gauge cluster package can be easily and neatly wired in. This includes JME ENTERPRISES, AUTOMETER, CLASSIC INSTRUMENTS, DAKOTA DIGITAL, STEWART WARNER, and VDO just to name a few.

Features and Benefits:
Dash and Main:
- A Bussman fuse box assembly and enclosed case mount in the LH door pillar area. Detailed photos of the installed unit are included in the instructions. Mounting bracket, hardware and a mounting template are included.
- Disconnects have been added for the engine and F/L wiring. They plug in under the dash and go out through grommets in the firewall.
- Can now be used with cars that have Factory Ford underdash A/C.
- Turn signal connector is for 1969-76 style GM columns. We provide the mating connector and terminals for the customer to adapt to their switch if using a stock Ford column. Corrected and updated tables demonstrate the proper wiring configurations.
- 12v switched and 12V battery radio feeds are included.
- Correct Ford headlight switch and connector.
- Connection to original Ford style plug-n-play wiper harnesses. Addresses the different wiper harnesses available along with detailed drawings and how to tie them into the dash harness (harnesses are no included with kit, but are available from most all Mustang parts vendors). Instructions for connecting a stock wiper/washer pump are included.
- Correct Ford ignition switch and connector.
- Complete detailed factory heater and heater resistor harness drawings, wires, and connectors included.
- Complete detailed neutral safety and back up lamp switch leads with disconnect drawings, wires, and connectors included.
- Console dash connections included that will plug directly into the factory console harness (not included).
- Detailed fog lamp switch connections and drawing are included eliminating previous questions about the stock third wire.
- Electric fan trigger wire is included in this kit.
- Complete dash cluster disconnect now included along with electric speedo wiring.
- Typical left and right courtesy lamp housings are provided.
- Cigar lighter connection is included.
- Relay and connections that control headlights, fog lights and horn are included.
- Glove box lamp connection is included.

Rear Body:
- Original 90 degree molded tail lamp socket connectors are included.
- Will accommodate aftermarket tail lamp socket connections.
- Original bullet style back up lamp terminals and rubber sleeves are included.
- Original fuel tank sender connection lead with the pass-through floor grommet is included.
- Feed wire and mating terminals to original style dome and sail panels lamps are included.
- Feed wire and mating terminal to original style trunk lamp is included.
- Original style mating terminal to accommodate tag lamp is provided.
- Third brake light wiring also provided in this kit.

New Gauge Cluster:
- Original light sockets, ring terminals and connectors to connect to a stock cluster are included.
- Includes feed to optional stock instrument cluster mounted clock.
- Includes aftermarket tach wiring.
- Just as with other similar Ford kits, this kit will not support the use of a factory tach (which has the ignition source routed through the tach assembly).
- Aftermarket gauge wiring terminals and instructions are included.

New Engine Harness:
- Complete engine wiring leads out to engine compartment includes: oil pressure, temp, electric choke, tach, 12v ignition.
- Supports a 1-wire alternator and also includes an exciter wire for use with other regulator style alternators.
- 6 gauge alternator charge wire along with (2) mega-fuses to protect the alternator and main battery feed to engine/dash harnesses.

New Front Light Harness:
- Aftermarket 2 post Ford type late model brake warning molded connector is included in this kit. Directions for connection are included.
- Complete wiring, terminals and connectors to connect to the stock parking lamp pigtails to create a disconnect system. Detailed instructions are included.
- Complete wiring, terminals and connectors to connect to the stock headlights. Relay protected for use with halogen lamps.
- Complete wiring, terminals and connectors to connect to single or dual horns.

Optional Extra-Cost Harness Kits:
- An extra cost optional 4-way hazard flasher kit is available.

Rear body harness assembly plugs into the main harness behind the left hand kick panel for easy accessibility and allows for original or custom routing.

*American Autowire recommends this kit for MODIFIED original vehicles, not OEM restoration projects.
*Does NOT support ammeters.

Installation Difficulty


Advanced skill is required for this installation.

Installation Videos

Vehicle Fitment

This product will fit the following Mustang years:

Rated 5 out of 5 by from Great update kit This kit has everything you need to update to a modern style harness. Has provisions for power windows and locks, third brake light and more. Directions provide fairly good instruction if you have a basic grasp of electrical circuits. I will say it was a bit intimidating at first but breaking it into sections really helps you not feel overwhelmed. Do make sure you either buy or rent the correct crimpers made for American Autowire. They make a huge difference in crimp quality and effort. It's not supposed to be a stock harness, if that is what you want, go with Alloy Metal Products.
Date published: 2015-01-18
Rated 5 out of 5 by from 65 mustang installation One of my 50yr old wires overheated and melted, causing a chain reaction that fried all my wiring. I bought this kit never having rewired myself. I used the instructions that came with the kit and the pictured instructions on CJ's sight. The instructions were on point. I started at 7am and finished at 7pm. I took my time, wrapped all the wiring branches in protective casing, and did it completely by myself. The car runs better than it ever did. Don't be intimidated by this kit. The labeled wires and the good schematics make this really easy. Time consuming, but easy. If I had someone helping I could've easily done this in a eight hour work day. Faster if I had purchased the AAW crimping tool(I straight up used needle nose to crimp all the AAW style wires lol). I highly recommend this kit.
Date published: 2016-10-30
Rated 5 out of 5 by from Contains everything but the kitchen sink! Not for the faint of heart! This is my second wiring kit, the first was for a 67 mustang. My recommendation is to not tackle this alone. Another set of eyes and hands is very helpful. This kit includes almost everything you need to replace ALL the wiring in your mustang. (when pulling your old wiring, leave the wiper motor harness and switch!) It even includes replacement ignition and light switches. Take your time and if you have any questions, don't hesitate to call their support line! Oh, also HIGHLY recommend their specialty crimping tool, worth the extra $80 bucks!
Date published: 2016-06-09
Rated 4 out of 5 by from Easy enough .. Lots of extra wire I got this to replace my faking harness while I hade the car apart ( replacing the cowl with the two peice cowl from Cj) it's going well now I havnt hade any issues putting it in ... The one thing I would warn is you have to find the correct wire crimpers the ones from aaw are not the only ones that will work .. These are GM style crimps also known as weatherpacks .. Search for those type of crimpers and you can find them a lot cheaper than AAW sells them.
Date published: 2015-01-31
Rated 5 out of 5 by from relays prewired and installed for most options Purchased for customer rebuild, I use american autowire for all my G M rebuilds. First time using for Ford, Very well made and fits well. No problems at all.
Date published: 2016-01-12
Rated 4 out of 5 by from Easy install I'm several months from installing this harness. I watched a video of it being installed in the same year Mustang that was also adding the new gauges I have purchased. There were some does and don'ts but it was their not thoroughly reading the instructions that created the problems. It looks straight forward and easy (if you follow the instructions). I'm looking forward to the install.
Date published: 2015-10-07
Rated 5 out of 5 by from Great features I recently purchased this harness to go in my 1966 Mustang Fastback!! Haven't got it installed yet but looks to be a very well laid out kit!! Excited about getting it installed and finished
Date published: 2017-05-02
Rated 2 out of 5 by from Not Painless... After replacing all the wires, my electrician noticed some parts were not designed for a Ford Mustang. The fuse box and other small parts were for a Chevrolet car. Electrician was able to adapt it, but for $700 I would expect better quality control... I shoudl have also checked each component more careful.
Date published: 2015-01-08
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Which crimpers do I need to buy?

Asked by: Earl
You can use any automotive wire crimping tool that can be found at most auto parts or home improvement store. We do offer this tool which should cover most of the wiring, 510586.
Answered by: rk cjpp
Date published: 2019-08-15

I have a 1966Mustang Convertible with a 289 no air but may add later. I'm am confused about the kit may not support an ammmeter, will this kit be good for my restoration?

Asked by: Gt75
You could also use part number 20120.
Answered by: rk cjpp
Date published: 2019-08-06

I want to know if this kits match with my Mustang 66 Fastback.

Asked by: Carmen de Mena
Yes it does.
Answered by: rk cjpp
Date published: 2019-08-05

Does this kit include all the original complete wiring of my 65 coupe? Including headlights, doors, trunk, taillights and dashboard controls?

Asked by: Jaime
Answered by: jmg1
Date published: 2019-07-25

Is this the correct kit for a 1965 with a later 302?

Asked by: John
This kit will work for the body and the gauges, it will also work on the engine if it is carbureted. If it is fuel injected you will need a separate harness for that.
Answered by: rk cjpp
Date published: 2019-06-26

Will this work with on a 65 mustang with the falcon-style instrument cluster? (idiot lights, horizontal speedo)

Asked by: EPS1117
I would recommend this harness.
Answered by: rk cjpp
Date published: 2019-05-06

Will this work for my '65 289 v8 coupe? Currently has mostly original wiring. Alternator has been replaced with a single wire alt. This is my first project car and am just starting to work on it, just want to make sure I'm buying the right kit.

Asked by: Alex
Yes this would be the correct kit.
Answered by: rk cjpp
Date published: 2019-04-15

Will this harness work with factory Rally Pack?

Asked by: Hozedog
No it will not, it will only work on tachs that use the negative side of the coil for signal.
Answered by: rk cjpp
Date published: 2019-03-16
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