High Amp Alternator

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Nov 6, 2002 | 07:07 PM

Willie

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From: Oklahoma

High Amp Alternator

I am hoping someone can help me. I understand only the basics of automotive electrical systems. I have a 1978 Ford F150 pickup that has a 460 V8 with a stock 60 something amp alternator. The whole system is stock with an external regulator.
I am installing some high amp draw equipment and want to replace the stock alternator with a 180 amp alternator.
My only question is, do I need to replace the stock regulator? I understand that the regulator only senses voltage and I was thinking that I should not have to replace it. Am I correct? If not, what kind of external regulator do I need to replace the stock one with?
Thank you for any help.

Nov 6, 2002 | 08:14 PM

Mike W

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From: Central Kali

High Amp Alternator

Your stock alternaton probably draws 2 amps max on the field terminal. Compare the resistence of the field terminal to ground on both. Unless the new one is a lot lower you should be ok.

I asked a alternator upgrade company about the duty cycle of an alternator. The response was "alternators can only run about 50% of their rated output for extended periods".

What brand did you get and how much if you don't mind.

Nov 6, 2002 | 08:27 PM

Willie

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From: Oklahoma

High Amp Alternator

I only paid $20.00 for it. A local parts store was going out of business and they had an auction for other parts deals in the area. I knew the owner real well and there were a few things that didn't sell in the auction and the rebuilt 180 alternator was one of the thing left. The alternator doesn't have a brand on it, only a rebuild No.
We mounted it on the tester and it registered 14.8 volt and 182 amps.

The regulator never really sees any high amps, right? The way I understand regulators is that they really only sence voltage changes.

Nov 6, 2002 | 08:48 PM

Mike W

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From: Central Kali

High Amp Alternator

Good deal on the price.

If it is not a Ford type, check to see if the field has one of the brushes grounded. On a Ford it is inside on the brush holder. Other brands may supply +12 to one brush and regulate the other brush ( controls current flowing to ground ).

The Ford regulator monitors voltage on the bat terminal. It changes the field voltage to maintain 14v or whatever it was set at. At low loads and high rpm, the field may only have 4 volts. At a high load and lower rpm, the field voltage may go to 12v as the regulator tries to maintain the battery at 14v. The highest current in the regulator is the current flowing thru the field terminal, typically a couple of amps.

Nov 6, 2002 | 09:08 PM

Willie

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From: Oklahoma

High Amp Alternator

It is a Ford type alternator. It will mount perfectly in the place of the stock one on my 460. It's a lot bigger in Diameter but mount just like the stock one. Thanks for the help!

Nov 6, 2002 | 09:29 PM

steve83

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From: Memphis, TN

High Amp Alternator

[updated:LAST EDITED ON 06-Nov-02 AT 10:29 PM (EST)]I'd go to an alternator/starter rebuilding shop & ask them to ID it for you, then find out how THEY recommend hooking it up. It's probably worth $50 to get THEM to do it right (with a warranty) rather than risk burning up a $300 alternator or a $50 battery, or a $3000 truck.

Nov 21, 2002 | 03:45 PM

Chia1

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From: Kwazulunatal

High Amp Alternator

Hi
If you say the alt on the bench put out 14.5v 182A it sounds like it has a built in reg otherwise at that amperage you would get close to 20V
Regards
Chia