[TheMonkey]

i'm converting my '61 generator to alternator.

i have a used alternator for external regulator (thx Stuart), and i'm wondering if i can use my existing firewall regulator from the orig generator for the ext alt?

any information i have dug up on converting from generator to alternator is either for internal alt or it also includes bringing over the ext regulator with the ext alt. (this includes info from my initial post last fall).

is any of this making sense? i'm wondering if i can just swap in an ext alt into '61 and plug in with a couple a wiring mods. oh yeah... if i can use my existing regulator, what would the wiring mods be?

thanks in advance, Scott.

[george kujanski]

Nope, it's a different regulator.

The DC gen regulator has a voltage regulating coil, a current regulating coil, and a cutout relay to disconnect the gen from the bat when the key is off.

The "A" body ext. reg for an alt has a idiot lite relay and a voltage sensing relay, no cutout relay nor current regulating coil is required.

The big car regulator (alternator cars with an ammeter or a chg/dischg gauge) have a voltage sensing relay.

George

[TheMonkey]

rats. thank you for the answer.

would my best route from here be to swap the ext alt for an int alt?

sidebar question: in the wiring diagrams that i see from int alt setups, it always shows that the R terminal off the back of the alternator always gets wired back directly to the battery. why doesn't it just connect to the BAT terminal inside the alternator?

[engineer]

just buy the ext. regulator and put it in. costs about $10 for aftermarket one.

[george kujanski]

For the sidebar question: The "R" terminal you speak of is actually terminal 2 on a Delco 10SI/12SI alternator and it is the Sense terminal. The internal regulator tries to keep this terminal at 14.0 volts so it's usually connected directly to the battery to keep the battery at 14.0 volts. Connecting it instead to the alternator output will keep that point at 14.0 but the battery voltage will then be less due to voltage loss in the cabling depending on your electrical loads.

I hate to say it but a "one-wire" alternator is the simplest choice for an alternator in your case; connect the output to the baterry and it's done. The downside is the sense point is at the output so it has the drawback mentioned above.

A standard 3 wire is not that much more difficult; run the large cable to the bat, add a smaller gauge wire to the bat, and then run a 14 gauge wire from the alt terminal 1 to an idiot lite in your dash. The idiot lite does 2 things, it, of course, acts as a idiot lite, and it excites ("kick starts") the alternator when the engine starts up. You coould also use a resistor instead of the idiot lite, but the lite is nice to have.

for more info go to www.madelectrical.com

George

[TheMonkey]

thank you. i think i have enough information to run with. i am going to attempt the multi wire arrangement. i just have a follow up:

my car has an ammeter, i don't think it has an idiot light (have not seen it and it does not show up on wiring diagram). currently, the gen regulator BAT terminal feeds a heavy gauge wire through the firewall, through the ammeter, and back to main battery junction terminal.

if i install a multi-wire alternator with a 63 amp variety, can the main BAT terminal off that alternator go through the firewall and through the ammeter with the original wire? or does it have to go directly to main battery junction terminal?

also, it looks like there is a resistor directly outside of the BAT terminal on my existing gen regulator (diagram has little squiggle, and physically can see a little barrel next to regulator). can i move this resistor and use it off of terminal 1 for the 'kick start'? if so, do i just wire from terminal one through resistor and ground it?

great info on the MAD site. they also said that you need resistance on terminal 1 or else car might not shut off!

Cheers,
Scott.

[george kujanski]

Scott, give me some time to check the wiring on the '61 so i can provide the best way to wire up your alt and maintain the ammeter.

George

[TheMonkey]

thank you very much George. if it would be helpful, i can scan in the diagram here tonight.

here's kind of where i'm leaning, and more importantly, what i'm learning....

-if my existing wiring through the ammeter (which i *think* is 10 gauge) can handle a 63 amp alternator i can hook BAT terminal to that. if my existing wiring cannot handle the alternator charge, i will skip ammeter and go directly to terminal. i'll wait for your opinion if i should go through ammeter or not.

-without currently having a charge idiot light, i could install one: run a 14 gauge wire from an ignition switched source (ign#1) through an add-on light then through firewall and into relay terminal 1. a diode is not necessary?

-i will connect terminal 2 to the junction terminal with 14 gauge wire so that any draw from accessories is included in the 'sense'.

really appreciate your help with this.

[george kujanski]

I think i came up with a diagram in the recent past per a post from 60Man....try a search in that forum or the electrical forum in the meantime.

george

[george kujanski]

Connect the large brown wire to the alt output, remove the old regulator and at the old reg connect the large brown wire to the wire that used to connect to the BAT term on the reg. That'll connect the alt to the bat thru the ammeter. Connect up the sense terminal and idiot lite circuit as you suggested. You only need a diode if you have a MSD ignition or if you have a HEI ignition that's gets it's power from a relay controlled by the IGN1 circuit.

george

[TheMonkey]

thank you George. i think that will work great. i feel like i learned a ton sorting through this. i'll feel better equipped when i tackle my bubble top this winter which will require a bit more attention.

i can't seem to find on the forum where we can vote which moderator most deserves to get paid?

i'll let you know how it turns out. i'm just bolting things back up this week from an engine getting pulled out.

[TheMonkey]

George-

thanks for your help! works great. on the relay wire, i used 14 gauge and put a 10 ohm 10 watt resistor in line. parallel to that i put a light. i used both, because the only reasonable DC light i could find had pretty small gauge wire and i wasn't sure if that would work okay.

the ceramic around the resistor gets hot like a bright light bulb, but i'll wrap in elect tape and maybe put it in a loom in a safe location.

thanks again. mission accomplished.

Scott.

[george kujanski]

Try a 56 ohm or so; it'll dissipate less power. 10 ohms is too small. you're above 10 watts in the resistor. No need for that, 56 ohms should be fine; about 2.5 watts.

George

[zbuickman]

George helped me put an alt in my tractor. It workes perfect!!!! I used a very small light. I have the power coming off the ign sw to a 1 amp glass fuse. to this DINKY little light with like 24 AWG wire on it. and thouugh a little switch there is no draw on this circuit. use the little light only and no resistor. I only put the switch there because I had it and it made wiring cleaner Ill post a pic or two. I used a delphi 85 amp alt

[TheMonkey]

thanks Brent-

i still need to clean up the wiring with a loom, perhaps i'll drop the resistor, but man... my light is tiny too. prob 24g wire also. it just felt funny because the relay wire from the alt was 14g.

[zbuickman]

here are some pics of the alt in the tractor. The charging system never was up to par and I only made the problem worse when I added an electric fuel pump and 1000 CCA battery. The 85 amp delphi Alt wired with 2 wires(idiot light and charge(letting it self sense))came out of an 87 S-10. I changed the pully to the v-belt one. I am going to do this change on my car as well However, Im going to use a 140 amp delphi unit for that.

P.S. thanks George I have not had a dead Batt since I did this. and I have power to spare.....it might get a radio

[zbuickman]

oh incase you want to use a delphi in the future hers the diag for it

[TheMonkey]

thx for the pics. looks like the light belongs there.

sooo... 104 amps in your car? wow.

tried my convert top for first time today. goes up like a champ. i used to have to give it gas if i wanted it to go faster, but it pretty much hits full speed at idle now. i only have 63 amp alternator or something but i guess that's all i need. the convert top going up pretty much pins the ammeter dash gauge on full charge though.

i tested for any draw while key is out and nothing going on. big new ground straps. hopefully charging woes are behind me on this car.

"all stand..... hand over your heart... may we never see the alt light while engine is running...."

[zbuickman]

That sounds Great

[cballweg]

Hi George,I was wondering if could help me on converting my 1959 Pontiac over from the generator to the alternator.I installed a 35 amp 3 wire 1969 GTO alternator on my 59 and was wondering from this article that I have to install the external GTO regulator or would a regulator from an older Pontiac work better since none of the 4 terminals are marked on the GTO regulator.You say to hook up brown output wire from alternator that is on the regulator generator terminal to the red battery wire that is on the battry regulator terminal together and then hook these up to the battery terminl on regulator,but I dont see any terminals marked on the 69 regulator.Also do I run any wires from the relay terminal from alternator and if so does this go to the regulator and which terminal?Help me Im confused.Thanks,Craig