• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

Converting 64 Falcon to EFI. Voltage Regulator questions

  • Thread starter Thread starter cobretti
  • Start date Start date May 17, 2005
C

cobretti

New Member
Oct 19, 2004
12
0
0
May 17, 2005
#1
  • May 17, 2005
  • #1
Hello Everyone,

I am starting converting my 1964 Falcon to EFI.

I will be using an EFI harness from a 1990 Mustang 5.0.

The motor I have is complete with all accesories attached so I will be using the mustang's alternator.

I want a clean engine compartment so I want to get rid of the falcon's original external Voltage Regulator. I hav a wiring diagram for my falcon and I have a few questions that I would appreciate some assistance with. All in all it looks as if 6 wires (4 conections as two wires connect to the VR and then continue) are connected to the VR.

1) According to the diagram a yellow and black wire runs from the starter relay to the "B" terminal on the VR and then on to the fuse box and ignition switch. I assume this is my "Hot at all times wire for the ignition switch as it also connects to the ciggarette lighter"
If I remove the voltage regulator where do these wires connect to in regards to the alternator wiring?

2) According to the diagram there is a white wire that runs from what would be the original falcon generator to the "F" Terminal of the VR. This wire ends at the VR. What does this wire do and what does the "F" stand for?

3) According to the diagram a yellow and black wire runs from what would be the generator to the "A" terminal on the VR and then on to the Generator indicator lamp. I assume this would trigger the light if the original generator failed. How do I connect this to the mustangs alternator? Do I connect the wire together where it joins the VR and then hook up the other end (the generator end) to the alternator harness? If so to what wire?

4) Finally, according to the diagram a red and black wire runs from what would be the generator and runs to the VR, (Cutoff relay?) What does this do and how do I hook this up to my mustang wiring.

Thank you for your answers.
 

MrBobMarley

Founding Member
Oct 7, 2002
460
0
16
Ft Myers, FL
May 17, 2005
#2
  • May 17, 2005
  • #2
Welcome to the boards. Aren't you the guy from svtperf with the black 65 fb? If so, I love your car man, sounds wicked in the video.

Now, as far as your questions, others on here know enough to answer them. I can provide some links though, to keep you busy until they reply.

www.fordfuelinjection.com

http://jr.stangnet.com/mustang.htm#top
(Jeff's 65 Coupe efi/t5)
 
C

cobretti

New Member
Oct 19, 2004
12
0
0
May 18, 2005
#3
  • May 18, 2005
  • #3
Thanks for the welcome. Nope, I am not the same guy you are referring too, wish I was

I did some more reading about voltage regulators and alternators and alternators last night. While it helped me understand things more it still leaves me with some questions.

I understand that the "B" terminal on the voltage regulator is for Battery. This wire in the 64 would run from the + post of the Starter relay to the "B" terminal of the voltage regulator, then continue on to the fuse box and then to the ignition switch and cigarette lighter. The 5.0 alternator I believe connects to the + side of the starter relay via a 14 Ga Dark Green wire that connects to an orrange and black wire and yellow wire (I don't know if this means a one wire alternator or two. Technically two wires join the alternator then join each other and that one wire then connects to the + side of the starter relay.

Now Connecting the new (5.0) alternator isn't the issue as it is pretty straight forward. I am wondering what to do with the existing falcon wires that run to the VR. I now understand that the "F" terminal on the VR stands for FIELD. Since the falcon had an external VR there was a white wire from the generator FIELD terminal to the VR Field terminal. The new (5.0) alternator should already have this connection since the VR is built in to the Alternator, so I don't need to worry about that one.

I now understand that the "A" terminal on the VR stands for ARM. The falcon would have had a yellow and black wire that ran from the ARM terminal on the Generator to the ARM terminal on the VR and then continue to the Generator indicator light. Looking at the falcon diagram it looks like the other connection on the Generator indicator light connects to the "RUN" terminal of the ignition switch. So I assume that if the generator failed it would ground the yellow and black wire lighting up the Generator indicator lamp. The new (5.0) alternator has a green/red wire that runs to the dash battery light then to the ignition switch. So I think I have this one figured out as well.

So that leaves me with what to do with the other two wires left over, the Black and yellow "Battery" wire and a red wire.

I think (correct me if I am wrong) I can do the following:

Black/Yellow Battery wire: Since the mustang alternator wiring will have its own "Battery" conection to the + terminal of the starter relay the only reason to keep the existing yellow and black wiring is to supply the "Hot at all times" to the ignition switch and the ciggarette lighter. So I think I can connect this wire directly to the + terminal post of the starter relay.

Now the red wire that would run from the generator to the side of the VR I am not so sure about. I think it is a ground and that it won't be necessary.


Anyone???????????
 

yeloxr7

Member
Apr 18, 2005
429
0
16
May 18, 2005
#4
  • May 18, 2005
  • #4
Ron Morris (www.ronmorrisperformance.com) sells an adapter harness for installing newer alternators in the older cars. I have one of these in my car. It was simple to install and it works well.
 
You must log in or register to reply here.

Similar threads

C
Electrical HELP! 1989 5.0 Stick, Voltage Bleed onto Ignition Trigger wire
  • ChickenDeluxe
  • May 14, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
225
Fox 5.0 Mustang Tech May 24, 2026
ChickenDeluxe
C
J
Power Wire Upgrade Question
  • jhaling
  • Dec 21, 2025
  • SN95 4.6L Mustang Tech
Replies
2
Views
253
SN95 4.6L Mustang Tech Mar 23, 2026
Noobz347
A
Resolved Electrical Help Please
  • Alabama
  • Jan 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
278
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 22, 2026
AeroCoupe
A
P0036 P0056 P0137 P0157 2020 Ford Mustang GT
  • AmkoA
  • Jun 16, 2026
  • 2024+ (S650) Mustang -General/Talk
Replies
0
Views
106
2024+ (S650) Mustang -General/Talk Jun 16, 2026
AmkoA
A
F
Electrical From scratch: alternator wiring
  • fox racer v2
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
0
Views
572
Fox 5.0 Mustang Tech Jun 23, 2025
fox racer v2
F
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?