Jim Smart
October 21, 2003

By now, most vintage Ford electrical systems have seen better days. As these old wizards of light, sound, and function approach the age of 40, their insulation has become old and brittle. Cuts and splices have taken a toll. Chafing and short circuits have, in some cases, left a smoldering pile of ashes. More and more creature comforts have placed an increasing strain on an old Ford's wiring. It's time for a new electrical system from Painless Wiring.

Painless Wiring has developed a Mustang/Falcon/Comet-specific wiring harness designed to thrust your vintage Ford ride into the 21st century. Not only does this wiring harness jibe with most of your Mustang's existing switches, lamps, and accessories, it also affords you power for just about anything you'd like to add. If you're interested in adding a powerful sound system, Painless can help. What about a climate control system? The Painless No. 20120 system is up to the job. Power windows? Bring it on.

We're going to visit JMC Motorsports in San Diego for our Painless Wiring system installation in a customer's '66 Mustang fastback. It is impossible for us to cover every detail here. However, we're going to cover the basics, looking over the shoulder of the very capable John Da Luz of JMC Motorsports.

Photo Gallery

View Photo Gallery

Photo Gallery

View Photo Gallery

Photo Gallery

View Photo Gallery

Photo Gallery

View Photo Gallery

Your main wiring loom installation should look something like this. It must all be wrapped, neat and orderly. It should also be anchored with zip ties or the like.

The Painless fuse box is the same size as the original factory fuse box. However, it holds 12 fuses and supports a greater load. Position this guy where the factory fuse box was. You may also locate the Painless fuse box anywhere you'd like.

The horn sounding system uses a relay in the Painless wiring harness. This is like the '64 1/2 Mustang electrical system. From '65 and up, horns are sounded directly through the horn switch. A relay takes the load off your horn switch. There is also a 10-amp fuse to protect the horn circuit.

Big-Time Protection The Painless No. 20120 wiring system offers you the protection of 12 fuses at the main fuse box, not including fuse protection elsewhere in the system. This fuse box is the same size as the original factory box for Mustang, Falcon, and Comet, with a greater number of circuits and fuses.

What's It Cost?
Chassis Harness, PN 20120: $589.99 (street)

What's It {{{Fit}}}?
'65-'66 Mustang '64-'65 Falcon/Comet