TheSamba.com :: View topic - Ford regulator on VW alternator? It works!!!

Fri Oct 11, 2013 7:27 am

Anyone know how to wire up the inexpensive old style Ford external regulator to regulate a VW alternator? My only concern is that on a VW Motorola alternator, one side of the field is internally grounded, so that means the regulator must regulate the positive side of the field. Not sure if that's the way Ford did it, as some put battery positive to one side of the field, and regulate the ground.

Did a little more research, and the later model Ford externally regulated alternators were "B Circuit", meaning the field is grounded on one side through its brush, and the other side gets positive from the regulator. That is the same as the VW motorola alternators. Should be compatible.

Fri Oct 11, 2013 10:30 am

Don't see why not if it's wired correctly. I've run Chevy a/c compressors on Jaguars, one-wire Delco alternators on my Belarus (Russian made) tractor, Chrysler power steering pumps and VW front brake hoses on a Mercedes, and a Capri rack and pinion on my woods buggy. If you're not a purist, then I say go for it.

Fri Oct 11, 2013 10:42 am

Those old style Ford regulators are around $15.00 and that's a darn site cheaper than the $125 they want for replacement Bosch regulators. Nearly the price of a new internally regulated alternator. If it's under your back seat, who would know which one it is?

Fri Oct 11, 2013 2:50 pm

Give it a try...keep us posted...I hope it works for you...good luck !

Fri Oct 11, 2013 3:05 pm

I'll definitely post the results and the wiring diagram if it works. There must be a lot of us who have those alternators from the mid 70's that had external regulators and would like a more common, lower cost replacement. The Ford one's were cheap as borscht and even had short circuit protection. I have a couple of them kicking around to experiment with.

Fri Oct 11, 2013 6:22 pm

These two diagrams from Speedy Jim might be of some help.

Sat Oct 12, 2013 3:09 am

I'm doing the exact same thing, I have already bought the Ford regulator, I just haven't got to that point of installing it yet. I found this diagram for wiring the ford reg to an alt using an external reg, have yet to test either method, I have another diagram I had drawn somewhere, when I get it wired up and confirmed the charging as it should, I'll repost here as well as a new thread I planned on starting to save people money using these. And these regulators, don't fail that often from what I've used in the past, the china ones....might be another story.

FLD = DF F on ford reg
STA = D+ S on ford reg
GRD = D-
BAT = B+

The Ford Reg uses these I = alt light A = to fused power S = D+ F = DF
Ground the body of the regulator well, I not only screw mine to the body, but add a ground wire from one of the legs I screwed down back to the neg side of the battery.

Depending on how big a hurry you're in, I'll be wiring mine up this week I believe.

Rich

Sat Oct 12, 2013 6:15 am

See below

Sat Oct 12, 2013 6:50 am

Northof49 wrote: I will likely try it today. If you hook A & S together and feed them from the wiring harness, that will be the point in the system to which voltage is regulated. So if accessories like lights pull down the voltage on the wiring harness, the regulator will increase the voltage output of the alternator until that measured point is at the regs set point. Conversely if you hook S to stator, it will directly measure the alts output voltage. I am going to jumper A and S together and hook to key on ignition. That's how I had it on my pinto motor in my ghia.

if you get it done today, and it works as it should, hand sketch a diagram, and I'll put it on a regular wiring schematic for all to see.
Also, do you plan on wiring in the alt light, either through the reg or from the alt as I believe these alt's need it to function??

Sat Oct 12, 2013 7:23 am

don't_bug_me wrote: Northof49 wrote: I will likely try it today. If you hook A & S together and feed them from the wiring harness, that will be the point in the system to which voltage is regulated. So if accessories like lights pull down the voltage on the wiring harness, the regulator will increase the voltage output of the alternator until that measured point is at the regs set point. Conversely if you hook S to stator, it will directly measure the alts output voltage. I am going to jumper A and S together and hook to key on ignition. That's how I had it on my pinto motor in my ghia.

if you get it done today, and it works as it should, hand sketch a diagram, and I'll put it on a regular wiring schematic for all to see.
Also, do you plan on wiring in the alt light, either through the reg or from the alt as I believe these alt's need it to function??

I will try it the simplest way, omitting the I connection on the regulator, and the D plus on the alternator. If that fails to charge, I will add a bulb from ignition to D plus and see if that is needed as an exciter. Some alternators need an exciter / idiot light to get the field started. I hear it depends on residual magnetism to work without it. Seems to me I have read posts on here where problems with that circuit caused failure to charge, so it's likely necessary.

Sat Oct 12, 2013 10:16 am

It works.

Here is the wiring:

Ford regulator

I Disconnected or idiot light (rather than D +)
A. Key on positive , such as ignition
S To D + on alternator and idiot light to positive key on
F. To DF

Alternator

D- To ground
DF. To F on ford regulator
D+. To S on ford regulator and through the idiot light to key on positive if you didn't hook a light up to the regs I terminal.

Sat Oct 12, 2013 10:48 am

I tested an alternative wiring that also works. Rather than hooking the idiot light to D+, you can instead hook it up to the regulators I terminal, and it also works.

So basically Rich,s right hand diagram works. Couldn't get any charge without an idiot light to start the process.

Sat Oct 12, 2013 11:26 am

Good to hear, I'll get to work on a nice color coded wiring diagram for everyone soon, I knew it would work, was just a matter of testing out which way to wire it, my baja didn't come with a reg when I bought it, and has the Bosch 55amp external reg alt, first thing that came to mind was the Ford regulator. $15 vs way too much, no brainer!

Sat Oct 12, 2013 12:03 pm

Northof49 wrote: I tested an alternative wiring that also works. Rather than hooking the idiot light to D+, you can instead hook it up to the regulators I terminal, and it also works.

So basically Rich,s right hand diagram works. Couldn't get any charge without an idiot light to start the process.

will do a proper diagram later using as mush of the wiring diagrams oem wiring color code as possible

Sat Oct 12, 2013 2:47 pm

When you get one of these alternators like I did out of a 1974 Beetle it's always a worry that you can figure it out and find a regulator that will work for it. I sent off for one like the VR-124, The colors match to the vw Colors when wiring it up!

VR-124 With Matching VW Wire Colors.
Standard Brand VR-124.

I found one on e-bay for like $15. which worked fine but it was a Wells VR-650. Looks like the same part.
The regulator gets it power from D+ on it's Red wire and supplies DF (green wire)which is the brush that is not connected to ground. D- needed to be grounded (brown wire) on mine as it floats when the brushes are well centered. The voltage regulator had no problem providing the 5 to 7 volts needed on the 5 ohm armature of the old Motorola VW Beetle Alternator. The Dash light in my 71 Bus works as excitation but it measured about 16 ohms it could be lower. But it all works fine. The Alt Dash indicator lamp also connects to D+. Just like in the schematic!
Regulator from Auto Zone.

Sat Oct 12, 2013 2:56 pm

Amazon sells those for roughly $30, and the cheapest on ebay was around $20, the Ford Regulators have been around for a long time, you can still get American made ones so you don't have to buy chinese, and they are always cheap and can be had at almost any parts store.

Yours does however provide another source, and you can never have too many.

Sat Mar 01, 2014 7:50 pm

Ford regulator. I just did this. It works great!

Sat Mar 01, 2014 7:53 pm

Next thing you know, you'll be wanting to run a Ford Pinto carburetor as well...

Sat Mar 01, 2014 8:06 pm

I know that my diagram is generic, but if you use the power wire going to the coil for the "A" connection on the regulator, then the only wire leaving the engine compartment is the "I" connection, on the regulator. going to the Negative side of your idiot light.

Sat Mar 01, 2014 11:51 pm

Jmoler1 wrote: Ford regulator. I just did this. It works great!

Very nice work. Thanks for taking the time to put that together.