[locomotivebreath]

I decided to add a vintage air kit to my otherwise stock 68 GTO . I’m going to use led lights , including head lamps , where ever possible . My original alternator is only the 37 amp variety . What does it take to run AC ? Can I buy parts ( the armature I’m assuming ) to increase the out put on the original 10dn ?

[Bill Hanlon]

Originally Posted by locomotivebreath

I decided to add a vintage air kit to my otherwise stock 68 GTO . I’m going to use led lights , including head lamps , where ever possible . My original alternator is only the 37 amp variety . What does it take to run AC ? Can I buy parts ( the armature I’m assuming ) to increase the out put on the original 10dn ?

Led lights would reduce current draw.

The heaviest current draw of the A/C is the fan. Check for the fuse rating on the high speed fan circuit (stock GM had a separate fuse for high fan speed, most Vintage Air systems do to) and then figure about 2/3 of the rating.

I'm no 10DN expert, but I'd guess you'd need a higher rated diode pack and external voltage regulator as well.

[george kujanski]

The alt of the day with A/C was 62A in a OEM flavor.

Rather than mess with changing internal parts just get a 62A or get a 10SI 62A (internal reg so a small wiring mod is needed) or get a 12SI 94A if you want some extra juice, unless, of course you want to keep the same external appearance.

george

[OG68]

If you're interested in keeping the original housing you can upgrade the windings to 63 amp. Not a bad idea to replace the diodes and brushes while you have it apart. Rotor is the same for both 37 and 63 amp alternators.

https://store.alternatorparts.com/partno27100.aspx

[JSchmitz]

I remember rebuilding alternators back in the day. Replacing the diodes, brushes, etc. Cleaning the armature. Those damn external regulators! Still hate those things! A lot of the replacement ones were junk. Better off getting a used one from the junk yard.

[padgett]

a) the more the better.
b) back in the day the stock alternator was a 37A
c) add AC or heavy duty and you got a 55A
d) some Chevrolets were available with the 63A
e) all used the same 10DN frame,
from memory so may be more.
ps I like CS144s (one wire)

[locomotivebreath]

Great info , it has been rebuilt to stock 37 amp standards , the. Vintage air came out with a kit for the 68’s . Upgrading the windings is what I was curious about , I guess I didn’t know how to ask the right way . I’ve had a few externally regulated cars and never had any trouble . My GTO now has 90k on the clock and the original reg worked fine when it was parked in 1978 .

[padgett]

The easiest upgrade is just to change the windings. Change both the spindle and the windings to get the max. They are mix and match,

[Formulabruce]

Originally Posted by locomotivebreath

Great info , it has been rebuilt to stock 37 amp standards , the. Vintage air came out with a kit for the 68’s . Upgrading the windings is what I was curious about , I guess I didn’t know how to ask the right way . I’ve had a few externally regulated cars and never had any trouble . My GTO now has 90k on the clock and the original reg worked fine when it was parked in 1978 .

You buy the stator kit and regulator, bearings, I can build your original 10 DN into a 10SI pretty cheaply. Or you can buy a 10si pretty cheap in many places and clock it for your application. You need a 10si (systems internal).

[F ROCK]

I've got eight amps in the living room, and a bunch more in the basement.
It's still not enough.

[stellar]

37 and 63 amp rotors are not the same. If upgrading to 63 amp stator, a 63 amp rotor should also be used. A 37 amp rotor with a 63 amp stator will provide higher amps than a stock 37 amp pair, but it will not be as much as a paired 63 amp set up.

[george kujanski]

Also mismatching the rotor and stator may lead to changing the cutin speed (alt speed where it starts producing output). Cutin speed too high and you get no charge at idle, think heavy traffic at night, lights on , etc. Delco spent a lot of time to design and test the alts so they have good performance.

George

[Formulabruce]

I have some 55 amp and chevy 63 amp rotors.
Also nearly Ever Si I have rebuilt doesn't get fully "exited" till at least 8-900 rpm, stock are like 1500 rpm.
That said, once excited, it will stay excited and produce around 20 amps at 500, and 30 at 650.
based on my experience.
SO, you start the car and rev it over 1500 just ONCE and alternators are typically good to go.

[stellar]

Comparing 10DN to 10SI alts is aples to oranges. Original post is about 10DN. Some 10DN and 10SI rotors are interchangeable and some are not. To clarify, they are physically interchangeable, but may cause problems when being used with a mechanical regulator. If using an electronic solid state regulator it seems like any rotor will work. I have seen many online complaints of new OE delco 10DN regulators being labled as defective. They are usually installed after the original alt has been rebuilt, replaced or upgraded sometimes with new OE Delco regs. being tried up to 3 times before going to a solid state reg with success. If you are going to be swapping rotors use an electronic reg .

[AG]

Originally Posted by F ROCK

I've got eight amps in the living room, and a bunch more in the basement.
It's still not enough.

Wow, that is the funniest thing I've seen in awhile! Good job.

[Formulabruce]

10Si is Internally Electronically regulated. Making his a 10si ( using front case half) or a different one makes no difference, its the most reliable way to go.

[i82much]

Originally Posted by F ROCK

I've got eight amps in the living room, and a bunch more in the basement.
It's still not enough.

it’s never enough …

https://www.youtube.com/watch?v=qmYt0e88ANo