Updating alternator - have a few questions

[Darticon]

Looking to upgrade from what I believe is a stock 60 amp to this 90 amp Powermaster on Summit.

First question: has anyone had any problems with Powermaster? It looks to be the perfect style I'm looking for with the right 3-wire connection...

Second question: If upgrading to 90 amp I saw I should also run a new charging wire over to the battery. I have some good quality 6 gauge cable - is that too overkill? And do I use a fusible-link and connect up at the starter relay?

Any insights would be welcome. Thanks FABO.

 

[krazykuda]

Watch the powermaster alternators. Some of them have internal voltage regulators and you have to read the listing very carefully to catch it.... You want the external voltage regulator if you have stock wiring...

Also, the one that you posted a link to says "One-Wire Capable: No"... If you have a 69 or earlier with the stock voltage regulator, it will take the single field alternator... It needs one wire capable...

 

[Darticon]

Watch the powermaster alternators. Some of them have internal voltage regulators and you have to read the listing very carefully to catch it.... You want the external voltage regulator if you have stock wiring...

Also, the one that you posted a link to says "One-Wire Capable: No"... If you have a 69 or earlier with the stock voltage regulator, it will take the single field alternator... It needs one wire capable...

Yeah, I've been trying to be careful instead of just hitting "order". This one is externally regulated and I should have mentioned it was for a 73 swinger. The back looks almost identical to what I have now with the power stud and 2 field connections.

 

[krazykuda]

Yeah, I've been trying to be careful instead of just hitting "order". This one is externally regulated and I should have mentioned it was for a 73 swinger. The back looks almost identical to what I have now with the power stud and 2 field connections.

View attachment 1714931638

73 should have a square back alternator with dual field connections...

If you have A/C, then get a double pulley...
If non A/C, then you need a single pulley...

 

[crackedback]

6 gauge wire will work fine for the charge line. Run it direct from alternator to starter relay.

 

[Darticon]

73 should have a square back alternator with dual field connections...
If you have A/C, then get a double pulley...
If non A/C, then you need a single pulley...

6 gauge wire will work fine for the charge line. Run it direct from alternator to starter relay.

Thanks guys. Guess this one I have may not be original then. Is there any drawback to having a square-back over a round other than cosmetics?

Also, one of these days, I need to get around to getting one of Crackedback's headlight relay kits... but this needs to be taken care of first

 

[crackedback]

Cool, not a bad idea to put a 10 gauge fusible link in the charge line.

Make sure the insulation on the 6 gauge is up to underhood temps.

 

[krazykuda]

Thanks guys. Guess this one I have may not be original then. Is there any drawback to having a square-back over a round other than cosmetics?

Also, one of these days, I need to get around to getting one of Crackedback's headlight relay kits... but this needs to be taken care of first

I don't think it matters as long as the alternator is functional and has the proper amount of field wires for your application...

But if I remember correctly, I once tried to put a square back alternator on a 68 car that originally had a round back, and the square back hit on the engine and could not fit... - that was a draw back...

 

[BillGrissom]

Some cars have a fuse in the alternator output wire, so a good idea. Indeed, one guy here recently posted about a "no charging" situation after an alt swap when he saw a flash at the battery. That was the charging fuse vaporizing because the alternator side was left swinging and the battery posts on. I recall a 1990's engine. I ran the charge wire to the battery, across the timing cover, as Magnum engines do. But, we don't know if you have a small block.

 

[Darticon]

Sorry for not putting up specifics, I should know better. It's an LA 318 with PS and no AC.

I think I've narrowed it down to returning to the square-back design with this 95 Amp 7519 instead of the 7018 I linked earlier - just wish it had a good image of the back...

I will most likely go with the 10-gauge fusible link over a fuse for the charging cable but it reminds me I need to get a fuse to put inline for the stereo amp cable I'm going to run.

Thanks Krazykuda, Crackedback and BillGrissom! I always need all the help I can get.

 

[AJ/FormS]

What are you running that you need such a large alternator?
I've never needed more than the 35A sissy alternator of about 1971 vintage.I just keep rebuilding it as necessary.Those sissys almost never need more than brushes or bearings, and you can buy one anywhere.

There's not much sense in running a 90, if you rarely use more than 10 or perhaps as much as 20.

 

[BillGrissom]

I agree w/ AJ. As long as the alternator keeps your battery charged, it is doing its job. A round-back works fine in my 65 Newport w/ EFI and electronic ignition. Electric radiator fans are the main load that requires more. Those began in FWD Mopars like my 82 Aries, which had the 70's square-back alternator. It vaporized the diodes every year, almost like clockwork. An auto electric shop told me that was typical. Always, the positive 3 diodes that aren't bolted to the case. I started band-sawing cooling fins into their rail, which made them last 2 years. I suspect the sideways orientation gave less airflow thru the alternator, since A's that use the square-back don't report such problems.

 

[Darticon]

What are you running that you need such a large alternator?
I've never needed more than the 35A sissy alternator of about 1971 vintage.I just keep rebuilding it as necessary.Those sissys almost never need more than brushes or bearings, and you can buy one anywhere.

Really just trying to future-proof it for now. The 60 amp on it now will run a decent stereo/amp combo but I've also been looking at a teardrop trailer an older couple have nearby. I've been trying to get the guy to sell it to me because I haven't seen them move it in the 4 years I've been at this location. Been asking them a bunch of questions and alternator came up because it has a power inverter/battery system in it for lighting/heat/stove... I guess it would basically be the same as a two battery system and didn't think 90 amp was all that big a jump if I decided to set it up for this. I've always kind of liked the look of one of these style cars towing a trailer like that - but I'm weird that way

I still haven't pulled the trigger on buying the new one yet. I have a friend at work here that said practically the same thing and offered to help rebuild the one I have. Going to do a little more looking into the one I have and decide from there.

 

[AJ/FormS]

You'd be way ahead, I think, to buy a stand alone generator for the trailer's heat and stove. They make them in many sizes now. Electrically speaking, it makes no sense to have to fire up your hot rod to make breakfast. Or,who's getting up in the middle of a cold night to fire it up, so you can be roasty-toasty.
The running lighting would be an add-on to your cars system.
The big alternators are not cheap, and when they are working hard, they are putting out more heat than watts. Nearly ten times as much, to my recollection. That can't be good for them.You may as well park the car with the nose under your bed on those cold nights, and crack the hood open.heehee.