The Stovebolt Site Forums The Shop Area The Electrical Bay 80 amp alternator with stock regulator?

Hi!
Can an 80 amp alternator be used with a stock (1964) regulator? If not, is there a regulator that will work?

Thanks!

64shrty,

I think the answer would be yes, but there are several catches. The 80 amps you note is the designed output capacity for the alternator. This is all well and good, but it's the voltage regulator that is adjusted for max current (amps) and will tell the alternator when to turn on or turn off.

Although I don't know this for a fact, I'll be surprised if you can find any stock voltage regulator that was set for 80 amps.

Output of this amount would have been found in later SI alternators that were equipped with their own internal regulators...quite capable of handling this amount of current, and sometimes more. A vehicle that used a alternator and external regulator wouldn't have had accessories that demanded a output of 80 amps...that's a lot of juice!

Are you sure you are clear on what system you have, internally regulated (SI), or the old externally regulated type.

If you are using the old external regulated alternator, it would make lots of sense to scrap it and move up to a more modern style. You could get an alternator with 150 amp output if you wanted.

Stuart

The old style points type regulator wouldn,t handle the field curent nessesary for that much amps. Like Stuart says you need the internal regulator alt. which has a solid state regulator. The regulator does not control the amps on an alt. It is regulated by demand. It will not go over it,s max output no matter how fast you turn it.

Stuart,

Yes, it's an external system. I bought a new 3-wire, 80 amp alternator from Summit several months ago. I installed it along with a new regulator and discovered just last night in pouring rain that my truck is running on battery power only-as the lights got dimmer and dimmer. Just as I pulled into my driveway, the engine quit due to no juice. After I charged the battery it runs again and all lights work. I checked the alternator and it's putting out 12+V depending on rpm so I think it's the regulator that went out.

Terry

Terry,

Both style alternators have three wires..the DA plug configuration would indicate whether it was internal or externally regulated. Unless you specically asked for it, I find it hard to believe Summit would even have a old style alternator...but I'm an old fart!

Make sure what you really have. DA plug on the back of the case is the old style, externally regulated. DA plug on the outer circumference of the case it internally regulated...the tabs appear like this --,not like this II.

Wrenchbender is correct about the current regulation of the alternator...I was wrong. This style regulator (not transistorized) would only have a field relay and a voltage relay. Max current would be a function of the alternator design.

While looking in the book I noticed that the old system was available with a transistorized regulator and a alternator rated at either 85 amps or 130 amps. I don't know what rig this was used on, but it's interesting.

Stuart

Ok, I thought the internal had one wire. The one I got from Summit claims to be an external and the plug is on the back.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D812102&N=700+0&autoview=sku

So, it sounds like the external regulator should work. It just won't put out 80 amps. True?

Yes Stuart there was a solid state external regulator way back. It was used on the big trucks. It was very expensive & prone to failure. It sounds like Shorty has the external regulator type alt. but I can,t imagine them selling such a critter.

Maybe I,m wrong but I think the required feild current would be too much for a point type regulator. Carquest has a solid state regulator as an exact replacement for the mech. one. I ordered a new reg. for my 71 buick I sold last year. When I took it out of the box I was surprised it was real light weight. I thought boy this must be cheap. Then I read the directions & it was a replacement for the point type. It was expensive but I wanted to keep it original.

Terry,

You da man! Your link shows exactly what you have described, and claimed to have in your first post...my most humble apologies.

If your truck has enough toys on it to pull 80 amps, the alternator you linked WILL supply that. I guess my next question would be, is your wiring up to the "oink" that this alternator 'can' supply.

The voltage regulator will try to maintain a max charge voltage of approximately 14.5 volts (max), but the amount of current your alternator puts out is based on what the system asks of it...up to it design rating. In your case, that's 80 amps.

This is how I understand it.

Stuart

Stuart,
Thanks! I don't feel like da man after my truck almost slipped off some jack stands today-but that's another story.

Well, I don't have ANY toys on my truck-not even a radio that works. I wanted a chrome alternator and that was the lowest amp one I found. The wiring appears "mostly" original. It looks original around the regulator and horn relay anyway. I'm sure it's not up to an 80 amp load but all I have is ignition and lights to run.

Terry

because the housing is chrome plated means it will run hotter than a normal cast type housing. heat disapation is always limited when a cast surface has been polished, it's even more so when plated. leaving the surface as cast and painted flat black helps disapate the heat from within. when the unit runs cooler the life span is usually extended (but not always).

Caroline & Jim

Thanks! I'll keep that in mind.

I found my problem was one wire on the plug on the back of the alt had broke off.

Terry

64shrty, refering to your old style alternator as a 3-wire is a sure way to add confussion. The 3-wire term is commonly used when talking about internal regulated 10SI and 12SI Alternators. Your alt is an external reg or a 10DN alternator.
Summit gets their high amp 10DN stuff from Quick Start. They sell a 80 Amp and 105 Amp kit to upgrade the external alt. They also have any diodes or bearings for them.
The 1-wire is a different animal because it has a different internal regulator. Often as not, guys put a three-wire on their car. Run one wire to it, then get on a forum and ask why it doesn't work right.
To add to what wrenchbender said, the battery determines the output from the alternator and that is why the battery should never be disconnected with the engine running.
The replacement solid state external regulators are not only light as wrench said, but can be identified by the lack of wound wire resistors on the bottom.
Quick Start doesn't sell a different reg for the high output 10DN and I don't see a need. The stator windings are what makes the difference. The field which is actually the rotor winding is not changed.

I think one wire is a confusing term. I had what I thought was called a one wire, 10si alternator, that had the main power connection, a field current connection that I tied to the main power connection, and an output I didn't use to the idiot light. Is this a "one-wire" cause their is one main wire that goes away, or is it something else?

I needed an alternator, and I paid like $30 for it rebuilt at my FLAPS. It was cheap, and worked (well, the second one worked, typical rebuilt crap for cheap). Was like 65 amp iirc.

Doug

One wire alternators started out as being born from a typical 10SI Delco internally regulated alternator. The basic original 10si came on the scene in the early 70s and lasted until the late 80s. Originally it had to have excitation wires plugged into it to electrically excite the internal voltage regulator. Aftermarket companies came up with the "one wire" internal regulator that excites off of RPMs. This does away with the two wires that plug in on a typical 10 SI. Keep in mind that you still have the battery terminal or output terminal on the rear of the alternator. This wire makes a bath back to the battery in some manner and is the only wired needed to the alternator, hence the "one wire" alternator. It makes for a cleaner wiring set up. The replacement regulators were called "self exciting" regulators and were a direct replacement of the original reglator without any modification. A down side to the original self exciting regulators was that the rpms to excite the alternators was to high to work well on some farm applications or even some automotive applications that had low rpm motors. This has since been solved with faster cut in regulators at lower rpms. What is so nice about using the delco 10 SI alternator in chrome or the old fashion version, is that they can be built to about whatever amperage you want up to around 80 amps if its done correct. There are kits that take them up higher but most dont last long to do the heat that is created. If you need higher amperage like this I typically suggested moving out of the 10SI and into the 12SI or even the later model CS-130 that could be modified into a one wire alternator. Hope this info helps out.
Ken
www.classicgenerator.com