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Hi, looking for some info as to either changing my 53 amp external regulated alternator to a 63 external regulated on my '72 Cutlass. Do I need to change the current regulator or will the current one be ok? I have also been thinking about going to the 63 (maybe larger ) internal style and would like to know what has to be changed to make this work ?
Last edited by yellowrocket; June 23rd, 2019 at 05:18 AM.
Reason: added car year
Get a alternator for a Cadillac or Olds 98, something Olds powered, with lots of electrical options. It should be a 78 or 94 amp. Upgrade the charge wire from the alternator to the junction block. It’s very easy to eliminate the firewall mounted regulator, either with a plug in adapter, or some simple wiring.
I believe Matt is suggesting the 12 SI alternator. I think 1985 or older. I bought mine from RockAuto to fit an '85 Caprice. Puts out around 80 amps. To convert the wiring, buy the American Autowire conversion kit. Simply plugs into your regulator connector and includes an adapter for the alternator as well. Costs $20 or so and is well worth the money.
One last comment. Matt suggested replacing the wire from the alternator to the bat since if the bat is completely discharged, it could pull max amps. The factory wire is really not rated for this amperage, I think it is 10 gauge and should probably be 8.
The rest of the wiring should be okay since a stock lights and accessories will not pull 80 amps, unless you have a radio amplifier, which should be on its own circuit directly to battery or starter terminal. I used starter post on my '68 since it is cleaner and I have OE repop battery cables from AAW.
Last edited by bry593; June 23rd, 2019 at 10:36 AM.
You can use either a 12SI style alternator or a CS130 alternator. The SI family looks more like the original 10DN, if you care. Order the alternator for a 1985-87 Olds Custom Cruiser with 307 and you'll get a 12SI with 78 amps. Order the CS130 for a 1989-90 Custom Cruiser and you'll get 95 or 105 amps. Both of these will bolt to your existing brackets. You don't need a kit to change the wiring.
I put a Jegs 10si alternator in my 71 98 that took a dump after 5 or 6 years, so I upgraded again. I ended up getting an alternator for a 1985 Chevy K20 pickup with a 6.2l diesel. I only had to get a metric bolt for the bottom of the alternator and use my drill to elongate the hole on the OE bracket. It works great, and I have an aftermarket amp with subwoofers and electric fan in my Olds!
and use my drill to elongate the hole on the OE bracket.
You can certainly make others work. My point about using the ones from a Custom Cruiser with the 307 is that there are no bracket mods required - it's a bolt-in
My point about using the ones from a Custom Cruiser with the 307 is that there are no bracket mods required - it's a bolt-in
Definitely a plus!
I think I read about the Chevy diesel alternator upgrade on the link I provided above. Hopefully nobody at the cruise-in can tell that it's a Chevy alternator on my Olds. Then again I guess they could see the Ford electric fan too. Hope the guy with the red beard doesn't see it.
Joe , thanks for the diagram. Am reading this correctly in that the only mod I would be doing is just splicing the wires to the diagram and that would be all? I have a few extra external regulators that are messed up and I was thinking of just gutting one and making all the changes inside so things look original.
That’s all that’s needed. It’s a easy swap, and unless someone knows what they are looking for (and are extremely nit-picky) it looks very stock and original.
A couple of additional items. As Matt notes, the 12SI will look somewhat original to the uninitiated. If you want to perpetuate this myth, open up the old voltage regulator, make the wire splices shown in the diagram internal to old regulator housing, and reinstall it on the firewall. Now you have bypassed it but it looks original. Also, you will need to change the plug that goes into the alternator.
The original 10DN uses this style:
The SI family uses this style:
The easiest way to bridge this gap is to use a conversion jumper sold everywhere. Note that you can even buy a kit that includes the jumper for the regulator plug. You can also simply remove the terminals from the original connector body and insert them into the new one if you don't want that extra "dongle" hanging off your alternator.
June 23rd, 2019, 05:17 AM
