Wiring diagram? Or just rewire the entire car?

[potato 10]

Yesterday I picked up a 1969 coupe.  The best way to describe this car is it has been somebody else's project car.  Its a base model 69 coupe.  There are no power windows or power seats.  A previous owner has swapped the 200CID for a 302 along with the usual things like aftermarket distributor, sensors, sending units.  Most of the electronic things on the car work as expected.  There are some things that are not working and some things that are just plane working wrong.  For example, some of the headlights dont light up, one of the blinkers in the hood doesn't blink, and when you pull the knob to turn on the headlights, it also turns on the heater blower.

I need to address the electrical in this car.  I have not come across a really great and comprehensive wiring diagram.  I have a bunch of ford shop manuals covering 1969, but they don't have much in the way about wiring.  Is there a good resource out there for a complete wiring diagram that is easy to follow for the 1969 mustangs?

And while looking into this, I am also considering trying one of those all-in-one kits to rewire the entire car.  I see a couple different ones on the market.  Is one of them better than the other?  I see some of them say they only work with the aftermarket 1-wire alternator and only works with aftermarket ignitions.  I think I would prefer one that worked with the stock configuration of the car and then let me pick and choose if I want to run a 1-wire alternator or MSD ignition box.  Do you guys have any input to which complete wiring harnesses to get and which to avoid?

Also, I have never rewired the entire car with one of these complete harnesses.  I understand the general theory behind it.  When it comes to the 1969 mustang, how far do you have to take the car apart to rewire it?  Do you have to pretty much strip everything out of the entire dash?  I will probably skip pulling the headliner out just to swap the dome light.  I'd splice the existing wire into the new harness.

 

 

[Mach1 Driver 560]

That's a pretty coupe! BTW, power seats and windows weren't available on the old Mustangs.

You will find a complete wire diagram for 69s in the "How Tos" section, its titled 1969 Mustang Wire Diagram... I wasn't very imaginative with the title. 

I used this diagram to backward engineer and make the only schematic for a classic Mustang. Schematics are intended to show "how it works" and is much simplified from a wire diagram. A diagram has all the wire routing, colors, splices, and plugs, etc. They both have their uses, but as an electrical engineer I would be lost without a schematic.

The schematic is up at the top of the same "How Tos" section and is titled "A Real Schematic".

Fire away with any questions. Another important resource we have here is a member who owns a harness restoration business. He goes by "Midlife", and without a doubt he knows more about the harnesses in our classics than anyone else on the planet.

Personally I wouldn't use one of those wire kits with the new types of fuses and relays. You can get most of your harnesses restored if you like, or buy all new OEM equivalents.  That way when you have problems (as most people do), we can reference a Ford diagram. If you use the kit, then neither Midlife or I can help you, since we have no details about how the kits are wired.

[potato 10]

7 minutes ago, Mach1 Driver said:

That's a pretty coupe! BTW, power seats and windows weren't available on the old Mustangs.

You will find a complete wire diagram for 69s in the "How Tos" section, its titled 1969 Mustang Wire Diagram... I wasn't very imaginative with the title. 

I used this diagram to backward engineer and make the only schematic for a classic Mustang. Schematics are intended to show "how it works" and is much simplified from a wire diagram. A diagram has all the wire routing, colors, splices, and plugs, etc. They both have their uses, but as an electrical engineer I would be lost without a schematic.

The schematic is up at the top of the same "How Tos" section and is titled "A Real Schematic".

Fire away with any questions. Another important resource we have here is a member who owns a harness restoration business. He goes by "Midlife", and without a doubt he knows more about the harnesses in our classics than anyone else on the planet.

Personally I wouldn't use one of those wire kits with the new types of fuses and relays. You can get most of your harnesses restored if you like, or buy all new OEM equivalents.  That way when you have problems (as most people do), we can reference a Ford diagram. If you use the kit, then neither Midlife or I can help you, since we have no details about how the kits are wired.

Thanks.  I wasn't sure what all options were available on these.  I have a 69 thunderbird and that thing is fully loaded from ford.  Power locks, windows,  seats, rear window defroster, even factory cruise control and ABS.  I wasn't sure if any of that was available on the mustangs.  The t-bird bucket seats look a lot like the mustang bucket seats.  Almost like they could swap right in.  If it wasn't for those pesky shock towers, I may have already been out in the garage swapping the 429 motor over.  :D

I am familiar with midlife harnesses from over on the 71-73 mustang boards.  He's got a great reputation there, too.  I don't know yet if I'll need his services on this 69 mustang.  I guess the first thing to do is find your schematic and start comparing it to this car to see what all's not the way its supposed to be.

[Midlife 814]

One other thing about most of the aftermarket wiring kits: they are basically designed for *gasp* GM products, so you'll need to cut off your Ford connectors and splice into the pigtails.

What you're looking for is more aligned with what I do: give you a factory correct set of wiring, all plug-n-play, with a 2 year warranty.  From there, you can modify things for 1 wire alternators, etc., as you see fit.

[JayEstes 172]

On 4/28/2022 at 8:48 PM, Midlife said:

One other thing about most of the aftermarket wiring kits: they are basically designed for *gasp* GM products, so you'll need to cut off your Ford connectors and splice into the pigtails.

What you're looking for is more aligned with what I do: give you a factory correct set of wiring, all plug-n-play, with a 2 year warranty.  From there, you can modify things for 1 wire alternators, etc., as you see fit.

If I were you, I’d pull the harnesses and send em to midlife.  They come back completely like original and you get a custom wire list.  Highly recommended service!

[Midlife 814]

Thanks, Jay.  You'll be getting your $20 in the mail soon, so watch for it! 

Just kidding folks, but thank you for the kind words.

[aslanefe 333]

6 minutes ago, Midlife said:

Thanks, Jay.  You'll be getting your $20 in the mail soon, so watch for it! 

Did you increase your referral bonus? I received $15 from you last week.

[Midlife 814]

Ooops.  Most folks get $40!  LOL