Full Wiring Replacement Question

[CV355]

It's definitely looking like a new wiring harness is in order for our '69 Mach 1.  The local shop that I trust is recommending American Autowire, but it looks like their "modern update" harnesses isn't compatible with 4-wire alternators.  I have a brand new 4-wire alternator sitting on a shelf, so I'm trying to avoid a 1-wire conversion.  I'm also seeing that some aren't compatible with gauge clusters that have a tach, and there is a 21 and 22 circuit version (A/C?).

Any advice on how to pick a system that will be compatible with what I have, and require the least modifications?  Is a 1-wire conversion worth it?  I can sell the alternator if needed, if there is a clear advantage.

 

[BattlestarGalactic]

My guess is finding any of the newer type harnesses that use the older external regulator alternator is slim.   The tach feature will likely not be included in any either.  They will assume you have an ignition system to cover that.  I think they lean this towards hot rods and such with lots of doo dads, not so much stock replacement.

I've used Autowire before and they are a nice system with well laid out instructions with full colored pictures.  The EZ Wire instruction manual is black and white and looks to be hand draw in pencil.  My .02

[gregaba]

I really like the Ron Francis wiring system. I have installed them in 7 or 8 cars and never had a problem. They will make you a 4 wire alt. harness and a tach wire if you order it.
Greg

[sixty9cobra]

I used the painless harness under the hood. It had everything that I needed. I have a MSD ignition so I needed a tach adaptor. I did need to reuses the plastic housing from the firewall connector. It did have the regulator wires and alternator connection but that was 15 yrs ago.

[chris401]

I used American Autowire in my truck last year. The thing I didn't like was it uses GM connectors. I ordered and re used the 65 OEM Ford connectors in most of the wiring. Although I did go to 3G at the same time I ran the exciter wire through the ALT bulb. Purchasing extra turn signal pins allowed me to make a jumper between the GM plug and the Ford pin type. The second horn relay has gone out. The dual horns worked fine through the OEM relay.

Concerning pickups the third brake light made an easy connection for the trailer brake box. Trouble is it is it is live with the emergency flashers on. There are ways around it.

[Bolted to Floor]

Painless didn’t have a wiring harness that incorporated my tach dash, took me some time to figure out how to make it work. It wasn’t the tach so much as the idiot lights for oil and alternator. Had my tach converted o modern internals by Rocketman Classic Cougars.

Converted to 3G alternator too. No more voltage regulators to deal with and a higher amp output.

[67428GT500]

I'm curious why you wouldn't go with a reproduction of the original wiring. They're all available and from one of the OE suppliers to Ford.
If you need information I would be glad to provide it to you. You also won't have to hire the work out being it all plugs in as Ford made it.
I replaced every harness on my Shelby during the restoration.  I don't think I would go the generic route on your vehicle.

                                                                                                 -Keith

[Falcon67]

Same on a Ford repop harness.  I use 3 wire (or 5) Gen3 type alternators rather than one wire.  Remove the regulator wiring from the harness, the same green/red wire that goes to the alternator from the 60s through the 90s will work plus the sense wire.  I jut pulled those old reg wires out of the harness on the Falcon.  The only one wire car here is the mini-denso alternator on the dragster.  I even replaced the Gen 2 fire starter on the 93 F-350 with a large case 100+ amp Gen 3, dropped right in.  I did have to add a 90A breaker to the power feed to the battery due to system load from the truck. 

[CV355]

I'm curious why you wouldn't go with a reproduction of the original wiring. They're all available and from one of the OE suppliers to Ford.
If you need information I would be glad to provide it to you. You also won't have to hire the work out being it all plugs in as Ford made it.
I replaced every harness on my Shelby during the restoration.  I don't think I would go the generic route on your vehicle.

                                                                                                 -Keith

I was curious about this myself, and actually the first thing I looked into.  Would it come with the green bulkhead connector / fusebox for the firewall?  That's one thing most of these kits didn't seem to have, so there would be no connectorization between the harness under the dash and the engine bay.

[My427stang]

There used to be a guy on VMF (Vintage Mustang Forum) funny guy, can't remember his screen name, but he was very capable and had a good rep.  Beauty is, he could likely modify to your needs.

Anyone remember?  Seem to remember he had an icon with him on a kids toy or something like that

[jmlay]

There used to be a guy on VMF (Vintage Mustang Forum) funny guy, can't remember his screen name, but he was very capable and had a good rep.  Beauty is, he could likely modify to your needs.

Anyone remember?  Seem to remember he had an icon with him on a kids toy or something like that

I believe your referring to midlife. He still frequents Vic as well as 69stang.com forums

[67428GT500]

Randy AKA Midlife is on several forums. I have his home phone number if you're in need of it. Keep in mind there are at least three reproducers of Mustang/Shelby wiring. Most have all the plugs in place. The bulkhead connector isn't difficult to work on for the 69 up vehicles. I will even loan you the tool for pin removal/installation if you need it.

                                                                         -keith

[jmlay]

I'm curious why you wouldn't go with a reproduction of the original wiring. They're all available and from one of the OE suppliers to Ford.
If you need information I would be glad to provide it to you. You also won't have to hire the work out being it all plugs in as Ford made it.
I replaced every harness on my Shelby during the restoration.  I don't think I would go the generic route on your vehicle.

                                                                                                 -Keith

I was curious about this myself, and actually the first thing I looked into.  Would it come with the green bulkhead connector / fusebox for the firewall?  That's one thing most of these kits didn't seem to have, so there would be no connectorization between the harness under the dash and the engine bay.

Engine bay bulkhead is available : https://www.npdlink.com/product/connector-headlight-harness-at-firewall-to-dash-harness/175771/202877?year=1969

[67428GT500]

Alloy metal products is the way to go. Jim was great and I even supplied a couple of rare original harnesses to produce new ones from.
Anyway, other than what is required to be removed for complete harness replacement it's a relatively simple job. I unwrapped the under dash harness and went through it on my 67 GT500. The right side door courtesy wiring had been damaged. I removed one from a non-tach harness I picked up. I also changed all the fuze clips in the box.  I have no doubt you'd be good to go with the replacement. The worst part is probably removing the fold-down seat interior quarter trim.
I bought a new harness for the tail lamps and wired sequentials into the car as well.

                                                                                    -Keith

[CV355]

Alloy metal products is the way to go. Jim was great and I even supplied a couple of rare original harnesses to produce new ones from.
Anyway, other than what is required to be removed for complete harness replacement it's a relatively simple job. I unwrapped the under dash harness and went through it on my 67 GT500. The right side door courtesy wiring had been damaged. I removed one from a non-tach harness I picked up. I also changed all the fuze clips in the box.  I have no doubt you'd be good to go with the replacement. The worst part is probably removing the fold-down seat interior quarter trim.
I bought a new harness for the tail lamps and wired sequentials into the car as well.

                                                                                    -Keith

I appreciate all the advice!

We actually stripped the interior out after work Monday and Tuesday this week.  Doesn't look like replacing the wiring harness will be too difficult if it's a direct-fit with the same connectors.  We found a few areas that were damaged or worn simply from age.  Everything in the engine bay was beyond repair.  This also gives me a chance to clean up the interior framework/paneling and put down Dynamat.  There isn't the slightest hint of rust anywhere thankfully, but the factory-original insulation has become orange dust everywhere.