One wire alternator ?
 

Ok guys i put a 100 amp 1 wire alternator on my 48 f1. From the Alt post the wire goes to the back of the amp gauge then to the batt and ign switch. Do i need another wire from the alt post to the batt positive because of the larger alternator?

Re: One wire alternator ?
 

http://www.jalopyjournal.com/forum/t...ammeter.72835/ Pete

Re: One wire alternator ?
 

What type of alternator? G.M.

Re: One wire alternator ?
 

Yes GM.

Re: One wire alternator ?
 

Briefly, if you only want to know how much current is going in to or out of the battery, then only the battery terminal is connected to one side of the ammeter. The alternator output post and all other wires (ignition switch, lites etc) are connected to the other side of the ammeter.

BTW, the standard 3-terminal 10si and 12si GM alternators can be easily converted to one-wires by simply connecting the #2 terminal to the alternator output post with a small wire and leaving the #1 terminal disconnected.

Jack E/NJ

PS: Use at least 10ga wire from the alternator output post to the ammeter and from the ammeter to the battery.

Re: One wire alternator ?
 

Lol he signed his post G.M. Because thats his login, he wasn't asking if its a General Motors alternator

Re: One wire alternator ?
 

I misread what you wrote. Dunno how I managed that. Mine is wired from the alternator through the amp gauge loop to the battery. I used a heavy wire so it barely fits through the amp gauge loop.

Re: One wire alternator ?
 

Again, if you connect anything but the battery on the battery side of the ammeter, you really won't know how much current is going into the battery from the alternator (charging) or how much is going out of the battery(discharging).

Jack E/NJ

Re: One wire alternator ?
 

On an F-1, there is no connection to the ammeter, it uses an inductive loop that the main power wire from the battery passes thru. That wire is then supposed to connect to the alternator output at the posts on the circuit breakers. That way the ammeter ("charge indicator") will indicate Net charge/discharge of the battery. If you put the alternator wire on the ignition switch (without going thru the loop for the ammeter), power to charge the battery will be going back thru the wire from the circuit breakers to the switch, and it isn't likely sized for full alternator output.

Re: One wire alternator ?
 

We're on the same wavelength Ross. You'll note that all the accessories, lites including the switch are on the alternator side of the ammeter loop. And the only thing connected to the battery side of the ammeter loop is the battery once the engine is running.

Jack E/NJ

Re: One wire alternator ?
 

my 2 cents..the one wire GM alt on my ford naa tractor will some times need to be excited, in other words it wont charge at idle when the batt needs it, I have to rev up the engine to see the amp gauge go to +. There is also a balast in the circuit. My understanding is a GM three wire alt with a diode in the third wire will charge at idle and is the exciter wire. I'm no expert but I bought a 3wire for my 34 project. Ken

Re: One wire alternator ?
 

Re: One wire alternator ?
 

I had 2 GM 1 wire 6 volt alternators someone gave me. This friend and his father put them on their 36 and 36 Fords, had them on about 2 weeks and didn't like them. Same problem plus not charging at idle or very slow speed. I put them on and found the same problems. I talked to the old wizard at a very old electric motor and generator repair place and he said he could put a 24 volt stator in them for $35.00 each and they would charge at lower RPM's. I had the stators installed and put them on one of my 39's and on a 36. With small stock pulley's they both charged at idle and low speeds and worked good only I didn't like the look of them on my old Fords. I made 7 6 volt alternators for my own use in the 39 type generator housings which work real good even at idle. What I did find and it took a while to figure out was when the battery gets real low they don't show a charge for about 8 or 10 miles. I suspect there isn't enough voltage after the start up load to excite them. This may be the problem with the GM ones also. The pictures show one I made with electronics all in the rear cover and plug in if I ever had a problem. It's been a number of years and no problems so far. G.M.

Re: One wire alternator ?
 

After experimenting with alternators for years I finally stumbled on a mid '70s Chrysler alternator with their dual input regulator. The regulator reads the field and the battery. Best I've found.