Alternator

[captain marty]

Has anyone used of have any thoughts about using a 6 volt 30 or 60 amp alternator on their truck?
Captain Marty

[me0418840987]

I have one on mine, since I had problems rebuilding mine, and the rebuilder that was local retired. Doesen't look proper, but then again, neither does the K/N airfilter, and the oil filter doesn't exactly belong, either. It does work well, though-no adjusting, or problems with overcharging. You purists may complain, but I like mine, just wish it was inside a generator case.

[captain marty]

Thanks for the input. What would I need to know before putting one on? I'm not all that good with electrical.
Marty

[me0418840987]

Nothing special. There should be instructions, and no wiring needs to be changed, if your wiring is all as original. All of the wires that are currently hooked to the cutout, get hooked to the terminal on the alternator. They say you should change the ammeter to a larger one, but I didn't and everything seems to be OK. Just that when the headlights are on, it tends to be at the top of the 20 amp gauge. It is basically a 6v positive ground 1 wire GM alternator. It will require you to bump the throttle to start charging each time you start the truck, it is not self exciting, and requires a certain RPM to begin. Just make sure that you clean the paint off of the bracket, engine block, and alt so you get a good bare metal to metal ground. I suggest that you order the brackets designed to go with this setup, as I got mine from someone else, and had to make the adjusting bracket, and H bracket. If I would have ordered the brackets, I think I would have had it installed in less than 15 minutes. Took me a good 2 hours by the time I made them. Tighten the bolts really well on the H bracket after you have your belt tension set, to avoid the bottom creeping around, as you will have an additional pivot point. NOTE: if your truck is pos ground, you need a pos ground alt. If it is neg ground, you need a neg ground alt.

[vtwinsideways]

As someone who chose to make his own brackets also, I must agree with the above post: buy them. I feel that I am a competent fabricator/metalworker, but the second time around, I will be buying brackets. Luke

Also: if you're going to put in an alt anyway, you may as well get a high amp model and install some good halogen headlights. Several years ago I went 12v and H4 with motorcycle lenses and reflectors in Deitz buckets. They are worth every penny! Nowadays you can get a nice sealbeam conversion that goes behind your original lenses that isn't obvious and you can stick with 6v.

[captain marty]

Lots of good info there, thanks. My wiring is a mess and not original. I don't even have any lights hooked up. I agree it would be good to get the 60 amp meter so my future lights can be good ones. I was told I will need to bump the throttle to start charging each time when starting my truck. Is this to get the polarity right? I'm running + ground. I will take a look at brackets and save a step. I plan on tackling the wiring soon.
Marty

[vtwinsideways]

It has nothing to do with polarity. Alternators have a higher rpm threshhold before they start charging. They need to spin a little faster to get "excited" than a genny does. Most of the modern kit-form alternator set-ups you can buy from Model A parts houses already have a smaller pulley to address this and some also have a different set-up in the internal electronics to deal with the lower rpm's that A's & AA's run compaired to the modern vehicles that stock alternators are made for. If you buy your alternator from a local battery shop or auto parts dealer, you will need to do some modifications that may include changing the pulley and/or adding a do-hickey inside. I have seen the internal kit somewhere, but I can't recall where. Long story short, it's easier to buy it in kit form (but more expen$ive) from one of the Model A parts distributors. Luke

[vtwinsideways]

I have a 12v GM one-wire on my A P/U. I bought it at a battery shop for $36, a smaller pulley from Speedway for $15 and spent the better portion of a day screwing around building brackets (the "H" bracket was the doosey, it had to be offset to align the pulley properly.) I can tell when the alternator is "excited" at night with the lights on. They dim at idle and come up just off of idle, so the pulley alone may not be enough for those who may be doing long parades (I mean really long, as an A ignition doesn't draw major amperage) or idling for long periods esp. with the lights on. Luke

[me0418840987]

I have a 12v GM one-wire on my A P/U. I bought it at a battery shop for $36, a smaller pulley from Speedway for $15 and spent the better portion of a day screwing around building brackets (the "H" bracket was the doosey, it had to be offset to align the pulley properly.) I can tell when the alternator is "excited" at night with the lights on. They dim at idle and come up just off of idle, so the pulley alone may not be enough for those who may be doing long parades (I mean really long, as an A ignition doesn't draw major amperage) or idling for long periods esp. with the lights on. Luke

Once you "excite" the fields, the alternator will charge properly, until you shut off the engine. If your lights are dimming at idle, it is probably a bad internal regulator. Mine does not dim at idle.

[SHELBY MESSER]

I was looking at an alternator on one of my Kubota tractor-mower. It is small enough to go inside a original A generator housing, and short enough I think for the regulator to also fit inside the case. I think with the reg. inside the original gen. case, maintaining the original look. I would have to make changes to the alternator, cutting the mounting brackets on the alternator. Also on the drive end, the pulley end, that would need to worked out to put the B- belt pulley. Maybe the original pulley since the kubota runs at a slower RPM. It always keep up a heavy-duty 12-volt battery. It will be a project that will take some time and figuring. If anyone may be interested in this setup I'll try ding it. I'm not interested in doing this for my A's I'm keeping them 6 volt like they have been for 81 or more years!!! Shelby, Louisiana.