The Ford Barn

john in illinois · 01-05-2014, 02:25 PM

I have a 39 generator and plan to have 12 volt fields installed. There are 30 and 40 amp voltage regulators. My guess is lower amperage. I just have the engine and lights to run-no accessories.

What regulator should I look for? I do not want a new regulator-prefer NOS or NROS. Something to think about while I look out at the Illinois blizzard today.
-19 tonight.

John

rotorwrench · 01-09-2014, 02:12 PM

This is a late response but here goes.

I would say that an early 2-brush generator modified for 12-volts would work with a 12-volt regulator from a 1956 to early 60s Ford (W/Generator). The current output should be set by the regulator. Most generators as small as a standard FoMoCo generator made in the era were good for 35 to 45 amps max. 12-volt systems don't need as much amperage as the 6-volt systems do to function with normal configurations. If you add power windows, seats, or lots of electrical accessories then a person should go with an alternator conversion for 50-amps or better.

40cpe · 01-09-2014, 02:30 PM

Just a question 'cause I don't know: Will a 40 amp regulator not function normally on a generator capable of only 30 amps? It seems any regulator is functioning below it's capacity when the battery is in a full or nearly full charged condition.

rotorwrench · 01-09-2014, 06:54 PM

The current limiter pole is set for just a bit over 35 amps on a normal FoMoCo type or replacement 35-amp regulator. The capability to generate more than the limit can do damage to the smaller capacity generators. The big Lincoln/Mercury 42-amp generator can take it but the smaller ones won't for very long.

If a person has the equipment to adjust the current limiter, the max capacity can be adjusted down on a 42-amp regulator unit to work with a 35-amp system.

john in illinois · 01-09-2014, 07:36 PM

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Thanks for all of your replies.

I have done some research since I posted this.My concern was not to overload the generator causing damage as mentioned. I have found that 56 12V fords without air conditioning had 25-30 amp regulators. Thunderbirds and Fords with air conditioning had 40 Amp regulators in general. The generator and field coils may be longer,i do not have a parts book or experience with 12 volt Fords.

I am going to go with 12 volt field coils and 30 amp regulator.

John

01-05-2014, 02:25 PM	#1
john in illinois Senior Member Join Date: May 2010 Location: Illinois Posts: 2,184	Voltage regulator amperage. I have a 39 generator and plan to have 12 volt fields installed. There are 30 and 40 amp voltage regulators. My guess is lower amperage. I just have the engine and lights to run-no accessories. What regulator should I look for? I do not want a new regulator-prefer NOS or NROS. Something to think about while I look out at the Illinois blizzard today. -19 tonight. John Last edited by john in illinois; 01-05-2014 at 02:30 PM.

01-09-2014, 02:12 PM	#2
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,431	Re: Voltage regulator amperage. This is a late response but here goes. I would say that an early 2-brush generator modified for 12-volts would work with a 12-volt regulator from a 1956 to early 60s Ford (W/Generator). The current output should be set by the regulator. Most generators as small as a standard FoMoCo generator made in the era were good for 35 to 45 amps max. 12-volt systems don't need as much amperage as the 6-volt systems do to function with normal configurations. If you add power windows, seats, or lots of electrical accessories then a person should go with an alternator conversion for 50-amps or better.

01-09-2014, 02:30 PM	#3
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,024	Re: Voltage regulator amperage. Just a question 'cause I don't know: Will a 40 amp regulator not function normally on a generator capable of only 30 amps? It seems any regulator is functioning below it's capacity when the battery is in a full or nearly full charged condition.

01-09-2014, 06:54 PM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,431	Re: Voltage regulator amperage. The current limiter pole is set for just a bit over 35 amps on a normal FoMoCo type or replacement 35-amp regulator. The capability to generate more than the limit can do damage to the smaller capacity generators. The big Lincoln/Mercury 42-amp generator can take it but the smaller ones won't for very long. If a person has the equipment to adjust the current limiter, the max capacity can be adjusted down on a 42-amp regulator unit to work with a 35-amp system.

01-09-2014, 07:36 PM	#5
john in illinois Senior Member Join Date: May 2010 Location: Illinois Posts: 2,184	Re: Voltage regulator amperage. Sponsored Links (Register now to hide all advertisements) Thanks for all of your replies. I have done some research since I posted this.My concern was not to overload the generator causing damage as mentioned. I have found that 56 12V fords without air conditioning had 25-30 amp regulators. Thunderbirds and Fords with air conditioning had 40 Amp regulators in general. The generator and field coils may be longer,i do not have a parts book or experience with 12 volt Fords. I am going to go with 12 volt field coils and 30 amp regulator. John