1966 F250 Alternator problem

jschirm · 03-09-2009, 09:38 PM

I have a 66 F250 that "had" a generator in it... it burnt out.. or at least.. the regulator did.. and it melted the guage on the dash. I replaced it with an alternator and new regulator and voltmeter in the dash... I can't get the thing to charge.

I've tested the continuity of all of the wires from the regulator to the alternator and from the alternator to the battery... but the darn thing won't light up.

I've returned the alternator and gotten a new one from a different store... still no charging...

I've run extra Grounding wires from the mount on the Regulator to the battery and from the Alternator to the battery... thinking maybe it was some sticky ground problem.. still nothing...

Any experienced old ford truck guys out there that can point me in the right direction?

ElectrolysisDoc · 03-09-2009, 11:49 PM

Well, what kind of alternator? Was this a kit? or from a bone yard? Any chance of a pic? That way we know which way to point.

Lets see,

I
Am a
Smiling
Ford

jschirm · 03-10-2009, 08:56 PM

It's dark out there now.. I'll take the pic and update tomorrow. The Alternator is the standard Napa brand replacement for this make and model... nothing fancy.. bolted right on the exiting mount.

jschirm · 03-14-2009, 06:04 AM

Here are two pics.. and to answer some of the other questions...

I did explain to the folks at the parts store that I was changing out a Generator for an Alternator and needed both an Alternator and a new Regulator to go with it.. so I'm hoping they gave me a Regulator to match the Alternator they sold me. As I mentioned, I did check to see that the tab labels on the Regulator matched up to the post labels on the casing of the alternator and I did use my ohm meter to make sure they all had good connectivity.

I'm wondering if I'm missing something obvious like one of the wires on the regulator should go straight to the battery instead of to the Alternator or something like that? Does anyone know of an online diagram for wiring these up?

ElectrolysisDoc · 03-14-2009, 10:49 AM

Quote:

Originally Posted by jschirm

.... Does anyone know of an online diagram for wiring these up?....

Some of my old text books from the 70's (yikes) would be perfect. I'll scrounge around.
Just so we know, would you mind posting the part numbers of the Alt and Reg?

Have you tested the wires at the regulator for voltage?
What did you use for wire ends, crimp on ends?

jschirm · 03-14-2009, 12:03 PM

Thank you very much for looking... I preformed the test perscribed to make sure the alt was working like it should... I can't repeat it back to you.. it was just a "follow these steps with your test meter" kind of thing and it did what it was supposed to do. I'll take some better pics of the alt and reg today and get the part numbers.

BroncoJoe19 · 03-10-2009, 05:02 AM

Since the RATE of charge is controlled by the PCM in newer vehicles, (and obviously a '66 does not have a PCM) would this come into play?

ElectrolysisDoc · 03-11-2009, 10:14 AM

Quote:

Originally Posted by BroncoJoe19

Since the RATE of charge is controlled by the PCM in newer vehicles, (and obviously a '66 does not have a PCM) would this come into play?

Sounds like a good old fashioned alternator/regulator setup BroncoJoe. Any bets on where the problem lies? The Ground?

*Oh, jschirm, snap a pic or two of the regulator also*.

While were waiting for more info, lets talk a bit about the early Ford alternator systems.
The regulator needs 4 wires connected to it. Remember that silly phrase 4 posts earlier? "I Am (a) Smiling Ford". Well, lets take the first letter of each word...IASF.... Hey! that's the pin out of the regulator!

I = ignition
A = battery
S = stator
F = field

What's that BroncoJoe? (from across the room) "What about the ground?

" Yep. Your right on it! The regulator must have a GOOD GROUND or it can't, umm, regulate!

The alternator takes mechanical force and converts it to alternating current. (The Wizard might use a term like "Electromotive Force" )
This is accomplished by creating a rotating electro-magnetic field that makes and breaks other static magnetic fields in the stator, causing a current to flow. And not just any current, a very efficient 3 phase alternating current is produced! 3 phase? Really? Like a commercial buildings? Well, yes, but smaller.

Once we have a good 3 phase current flow, we need to convert it to DC to make it useable. (The Wizard might use a term like "Rectifier Bridge"). The Diodes in the back of an alternator do the job of cleaning up the current by converting A/C to D/C. Now that we have an ample supply of D/C power, we can distribute it to the battery and other load systems like lights, modules, ignition, fans, etc.

(yelling from across the room) "THE GROUND! THE GROUND! Don't forget the ground!

" Right, Right, BroncoJoe, Without a good ground, this alternator will not charge! The alternator simply can not push out current without a good ground. Like trying to jump while standing in the mud!

The next step is to let the regulator control the alternator output, by controlling the field. You can control a hundred amps at the output terminal just by regulating 5 or 10 amps to the field. Incredibly efficient. Other wires in out circuit are are stator which is a special "communication" feedback circuit from alternator to regulator, ignition switch signal and battery reference to the regulator.

And yes BroncoJoe, the most overlooked circuit:
THE GROUND!

theoldwizard · 03-11-2009, 06:41 AM

So did you buy an appropriate voltage regulator ?

BroncoJoe19 · 03-11-2009, 11:48 AM

LOL.. that's funny!

(yelling from across the room) "THE GROUND! THE GROUND! Don't forget the ground!"

hehehe... next you'll have me running on a beach yelling... "the plane, the plane!!!"