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ss396t6
12-25-2014, 08:51 AM
What was the part number of the original FOMOCO voltage regulator on '56-'57 Thunderbirds?

Thanks!

jopizz
12-25-2014, 11:32 AM
The part number shows as B7A-10505-B. However the numbers stamped on the regulator could be 2700015 or 2900424.

John

simplyconnected
12-25-2014, 03:57 PM
Truth is, they matched the current output of the generator with the regulator. If your generator produced 30 amps, then you need a 30 amp regulator. Some guys use a Jeep regulator in a jam because it works.

Regulators simply cycle the field power in your gen, which causes the armature to produce more or less current. Regulators have a 'cutout relay' that disconnects from the battery when the key is off, so your battery doesn't drain over night.

Make sure your GEN light bulb works. It 'jump starts' the armature upon starting. - Dave

ss396t6
12-25-2014, 05:15 PM
Thanks all.

I bought a nice original 2900424 off of eBay recently but the applications I have read were for 1958-1962 Thunderbird. There is a blue unmarked after market regulator on my '57 that I want to replace.

jopizz
12-25-2014, 05:50 PM
Since that part number is specified in the Master Parts Catalog for '57 I would think it would be "concours" correct if that is your concern.

John

ss396t6
12-25-2014, 07:34 PM
Since that part number is specified in the Master Parts Catalog for '57 I would think it would be "concours" correct if that is your concern.

John

I am also an NCRS member and all I hear is Top Flight and correct this and correct that. I do lean toward correct but concourse is not my goal. Our cars are over 50 years old. I'm over 60 years old and I'm not concourse but I do still have all my original parts. I just wish I looked as good as our cars.

simplyconnected
12-25-2014, 10:24 PM
What was the part number of the original FOMOCO voltage regulator on '56-'57 Thunderbirds?

The part number shows as B7A-10505-B. However the numbers stamped on the regulator could be 2700015 or 2900424...

I am also an NCRS member and all I hear is Top Flight and correct this and correct that. I do lean toward correct but concourse is not my goal...I'm trying to figure out your point. You asked for correct part numbers, John gave them, now you don't like it. What do you really want? It's simply a 30-amp regulator.

Why don't you drop the old generator and regulator, and fit a good self-regulating alternator in its place? - Dave

ss396t6
12-26-2014, 08:51 AM
I'm trying to figure out your point. You asked for correct part numbers, John gave them, now you don't like it. What do you really want? It's simply a 30-amp regulator.

Why don't you drop the old generator and regulator, and fit a good self-regulating alternator in its place? - Dave

Whoa and Merry Christmas to you, too, Dave!
I never said or even implied "I don't like it". I assume jopizz is John and I sincerely appreciate his information. I am a newbie at this and I don't have a Master Parts catalog. I was merely trying to ascertain if the 424 also applied to '57. I now have a 2900424.

simplyconnected
12-26-2014, 10:27 AM
...I am a newbie at this and I don't have a Master Parts catalog. I was merely trying to ascertain if the 424 also applied to '57. I now have a 2900424.Yes, Jopizz is John. He does have a Master Parts Catalog. He is very helpful and comfy with his and other T-birds.

If John cited a 2900424 is included as an OEM and you already have one, it doesn't get any better than that. Ford used a host of regulator numbers and brands (like Bosch) across car and truck lines. John only cited T-bird. If you add all the cars (Ford, Mercury, Lincoln, Edsel), tractors and trucks (we always sold more trucks than cars), you quickly realize that it's impossible for one company to make millions of production and service regulators in one year. Although the part number didn't change, Ford used a vendor number to identify the parts. All the regulators work equally as well within the same part number.

Happy New Year - Dave

ss396t6
12-26-2014, 06:35 PM
Yes, Jopizz is John. He does have a Master Parts Catalog. He is very helpful and comfy with his and other T-birds.

If John cited a 2900424 is included as an OEM and you already have one, it doesn't get any better than that. Ford used a host of regulator numbers and brands (like Bosch) across car and truck lines. John only cited T-bird. If you add all the cars (Ford, Mercury, Lincoln, Edsel), tractors and trucks (we always sold more trucks than cars), you quickly realize that it's impossible for one company to make millions of production and service regulators in one year. Although the part number didn't change, Ford used a vendor number to identify the parts. All the regulators work equally as well within the same part number.

Happy New Year - Dave

Thanks and Happy New Year to you, too, Dave.

Although Fords have been in my family over a period of many decades I have personally been a Chevy guy for the last 30 years. I have loved the Thunderbirds particularly the years from 1955-1966, 1957 specifically.

After reading the output information about the 1957 generators and their particulars I noted that the original voltage regulators had the same information. I also learned that 1957 generators are unique to themselves. I was offered a chance to switch over to an alternator but at this time I want to keep things as original as possible.

paul274854
12-26-2014, 10:26 PM
The last regulator I bought for my 56 was also blue. All I did was paint it black and added a decal to the top which had all the correct numbers.

If your regulator is working ok, just do what I did.

I have had my 56 for 6 years. never had an electrical problem other than a regulator that went sour on me (no telling how old it was as it was on the car when I bought it). Unless your running air, a generator works fine. I have had more problems with alternators than with generators. On another car I have that was previously converted to an alternator, I went through three of them before I got one that worked properly.

simplyconnected
12-27-2014, 02:05 AM
My '55 Customline was 6-volt positive ground. It had a 272 Y-block with a crossover exhaust pipe that ran in front of the engine. I still laugh just thinking of it.

Our '59 Galaxie is a 292 Y-block. I did overhaul that engine but I switched to an alternator and electric fan so we could run it in parades all day (the Woodward Dream Cruise) at idle speed. It worked out perfectly and I couldn't be happier with the alternator setup. That, the electric windshield wipers and power disk brakes on radial tires are the best retrofits. I will never go back to stock.

Voltage regulators have two long resistors clinched to the back side. They are famous for getting brittle and breaking. If you 'manhandle' them the resistors can break as well. Rarely do the relays go bad. Just exactly WHAT do the resistors do? A regulator compares the battery voltage to the generator voltage. Since the 14-volt generator needs to overcome 12 volts for charging the battery, Ford threw in resistors to make the two 'even' when the battery is full. Otherwise the generator would never stop charging.

Think about this; OEM Voltage Regulators don't care which polarity they are connected to. There are no diodes, but simple relays and two resistors. They can run with positive or negative ground just the same. Most do not say whether they are neg gnd while others do, just to let you think you're buying the right one. The truth is, there is no polarity in a Ford regulator but there is in the generator. That's where your GEN light comes in, to 'tickle' the armature into making a tiny bit of magnetism before it starts turning. - Dave