Alternator AMPS
 

What is the stock amps to an original 65 GTO alternator with no AC? Is there any benefit to replacing with higher Amp alternator with Pertronix Ignition?
I need a new one and don't know what amp to buy.

Thanks, Dave

No harm in going to a 62 Amp alt even if your electrical loads are light. The regulator keeps the voltage constant and the alt output current will be whatever the electrical load demands.

To answer your question, I believe the alts available were 37 A, 55 A and 62 A. according to the electrical options/accessories in the car.

George

What I remember about 10DNs in early 60s was: (no guarantees from memory)
37A Base normal cars
42A base Corvette
55A HD and AC normal cars
63A Corvette HD & AC

Also you could mix and match rotors and stators to make "others".

First off what do you mean by what you have, are we just talking about just the Pertronics brakerless Distributor conversion? I

If so I would not even bother as your Pertronics does not even eat up 1/4 as much current as the cars cigarette lighter does when in use!

Plus some of the bigger ones are clocked different in terms of the rear connectors and you have to remove the 4 bolts and carefully move the ass end without popping the 2 brushes out!

Now if your taking about the Pertronics digital box, that draws 1.2 amps per 1000 rpm.
At 6000 rpm that would be 7.2 amps , and most cars cigarette lighters are on a 10 amp fuse.

In fact if you do not smoke that’s a perfect place to hook up such a control box, other wise you would need to hook it up to the fuse boxes unused Acc terminal and then fuse it at like 8 amps and run 12 ga wire.

Thanks all,
you don't know how much of us dummies appreciate your help all the time. I will just go with the stock 37 or 42 amp.
CAR GUYS ARE GREAT

OH, yes Steve, it is just coil and module.

It's not worth the time or trouble to install a stock, low-amp alternator. Unless you've done some diagnosis, you won't know if the alternator has failed, or if it's the voltage regulator, or the wire harness in-between. Replace the whole mess with the next-generation of internally-regulated alternator. Dirt cheap at any parts store, you may need to "clock" the rear housing to make it fit your application better.

Every vehicle I own that used to have an external-regulator alternator has been converted to a 10- or 12SI internally-regulated alternator of at least 60 amp output. The big improvement is in LOW RPM charging, even if you don't need the higher amperage at higher speed.

Converting from the junky original alternator to the 10SI/12SI is a matter of one wire harness pigtail, and two home-made jumper wires. The alternator itself bolts right in, and even looks somewhat like the original.

The pigtail assembly is available at any auto parts store. Part number vary, but every parts store will sell their version of the thing. The color-coding on the wires is wrong, but no one sees that if you wrap it with electrical tape...or keep the hood shut.

https://www.summitracing.com/parts/tff-7520a

The two jumper wires can be made with four 1/4" blade crimp-on terminals, and two, 4" pieces of 16, 14, or 12 gauge primary wire, some solder, and some heat-shrink tubing. They plug into the existing electrical connector for the external regulator. Connect terminals F and 3, and 2 and 4.

If don't care about originality and have room, it is hard to beat a 140A CS-144.

Ant it so funny that so many of these well over 50 year old cars still run just fine with 37 amp Alternator, I guess electricity hasn’t kept up with the times in terms of the need to brag about and to have excess!

Over the years I have replaced far more internally regulated Alts then external, and when the external systems had problems 90% of the time it was the regulator on the firewall that had the problem.

If your car ever over heats badly you can count on very shortly having the internal regulator portion of the Alt going south on you.

BTW reclocking is a matter of removing 4 long screws & rotating the body. Do not pull apart, do not need to reseat brushes.

ps increased longetudity is why I run all cars about 20F under stock. 180F therostat in computers cars, 160F in non. Either gives good heat.

Does the 140A need a larger 12V wire?

The output wire? I suppose that'd be best, but not essential unless there's added accessories that are going to be drawing more current.

As said, the big deal with newer, high-output alternators isn't the big numbers of the rated power--it's the improved low-rpm charging ability.

My car has Sniper EFI and will soon have Vintage Air. I currently have a 100 Amp alternator and curious if I should step up to the 140A.

Agreed. Have had the volt meter on my cars with the original 35/37 amp alternator take a dive at night with all the accessories operating (including stock and aftermarket), especially in traffic. A higher output alternator sounds good to me.

Does the 100 amp alternator have problems supplying enough power, especially at idle and residential-street driving? If it's working well for you, there's no point to upgrading.

100 amps is a lot of power. Unless you are doing sound competitions I really doubt you need 140A

I went with a 140A internally regulated alternator for my '66. I will be running an electric fuel pump, AC, and will eventually add EFI. May also add an electric pusher fan if needed. 140A may be overkill for me, but the price is basically the same as 100A so I figured having some headroom wouldn't be a bad thing. I want to keep those headlights burning bright.

CS-140 is nice, improves low rpm output
12si's are also good, but lower output at lower rpms compared to CS-140
I've worn out a few 12si's (i have a hardcore stereo system and many electric bells/whistles so to speak), the CS-140 has been a nice workhorse for sure

There's some other alts on the market too, MEGA alt and another one that have some VERY nice output at low rpms

it's always a good idea to upgrade the charge wire, but again that depends on your draw
also, make sure you use a very good belt if using a V belt to drive high amp alts
Serp belts will have less slippage and better at low rpms when the ALT is working hard
and as always double check your grounds and make sure they are good, and YES... some of these high amp alts need an additional ground wire on the casing, READ your install instructions

ALSO.... BE weary of high output claims.... some just change pulley size to speed the alt thus making claims on such mega power.... remember that will heat the ALT up more, so keep an eye out on that

as for dimming lights there are many factors....
battery (not all are created equal), battery cables
Alt (amperage of course at various speeds, along with the load)
grounds
headlight relay kits (painless makes a GREAT one)

speaking of headlights and a little off topic but i can not rave enough about the VisionX LED headlights.... Ultra bright, great spread, super white, and VERY low power draw.... something to consider....

Well consider that my usual configuration is AC, air horns (like big boy - compact and loud), bluetooth handsfree, & assorted electronics, cheap overkill is good (stock CS-144). Also buy only AGMs any more.

Out of curiosity has anyone used this alternator company?

https://www.qualitypowerauto.com/ite...-6.6-Mount.htm