12 V alternator choice
 

Ok, Ok, stop your moaning.... this is being done because of a medical condition dealing with heat, been hospitalized twice with heat stroke! I believe the medical term for this condition is called ALICE or in some areas SALLY! So AC seems to be in the future. Most alternators on A's (6 or 12 volt) seem to be
"1 wire". I have been told these can be hard to find should one fail on a road trip. Would a "3 wire" with an in line diode be a better choice with the thought of on the road replacement from the local auto parts store? What would be a better choice a GM 10 SI or a 12 SI? I hope to complete this project in time for this years tours so please hold back on the well deserved sarcasm and those who have made this change please share your expertise. Thanks

Re: 12 V alternator choice
 

I'm thinking whether it is ALICE or SALLY, its got to be a bitch.

Either of those alternators will do the trick, even the small Nippon unit at 55 amps should handle the ACs components (fans and clutch). It's going to slow you down a bit, so I'd go with a very small compressor to limit engine drag. Worse, where do you hang the condenser? In front of the radiator will look pretty bad, so I'd stow it under the car with a good fan on it.

Good luck, stay healthy...

Re: 12 V alternator choice
 

I have been using the GM 10SI For several years, bracket made from shackle, small diameter pulley available from venders. one wire ,self exciting regulator . starts charging at 1200 RPM . no issues . I purchased a spare regulator because I was told it would fail, maybe it will, maybe it won't. Less than $125 CDN

Re: 12 V alternator choice
 

Been using the GM 10SI for many years. On a road trip to Nashville we had to replace one. Bought it from O'Rileys and it was self exciting. All the cars (6) on the trip had AC installed. No problems keeping the battery up.

Re: 12 V alternator choice
 

For long distance reliability with a 6 volt system the only realistic preparation for an alternator failure would be to carry a spare. I have converted many 12 volt 1950s and early 1960s Fords from generators to alternators and always used late 1960s Ford alternators with external regulators. Don't think too many folks are using external regulators anymore but troubleshooting a failure is pretty easy and the old style regulators (including modern electronic units) and alternators are readily available. My 31 Tudor has a 12 volt one wire alternator and works fine.

Re: 12 V alternator choice
 

I have been in auto electric business over 30 years and have built hundreds of 10si 6 and 12 volt units, neg. and positive grd. These are very reliable units and easy to service. The one wire units with internal resistor will excite at lower rpm but can cause battery draw over long times of no use. Unit with inline diode will turn with key, one wire requires alternator to rotate at a set rpm to excite and can turn off when idle. I have used the small Nippon alternator on some other cars and tractors but belt sometimes it's hard to match pulley, shaft size on Nippon alternator is smaller so you have to find a wide pulley. All will work.

Re: 12 V alternator choice
 

GM10SI one wire, Brattons bracket and pully. This setup is easy and all parts stores can get you a GM 10SI not to mention junk yards in an emergency.

Re: 12 V alternator choice
 

Vince is right on...

I will add that most little Nippon alternators (the ones with a V belt pulley), have enough meat to stick it in a lathe and widen the groove to fit the stock model A belt. Great little alternators, I've used several now in cars and tractors, never paid more than around $50 for one, new, on eBay, with free shipping. Carried in most auto parts stores for tons of foreign cars in an emergency, but the bargain is on eBay. Easy to make mounts yourself. Have yet to have one fail. Caveat: No 6v version, and no pos. ground version that I know of.

Re: 12 V alternator choice
 

Thanks to all the "Barners" for taking the time to share there knowledge about alternators.
Sure helps me to move forward with my project. I have done a lot of research through the forum and with Western Model A Club members to get a good understanding to do this project right the first time. What a great Forum comprised of Model A Ford lovers.

Re: 12 V alternator choice
 

Short cut... Nurex, whole GM package including bracket, adjuster and hardware. On sale now for $191. Worked for me... Chap
https://www.nurex.com/alternator-12-volt

Re: 12 V alternator choice
 

Randy Gross who sells the Drum Brakes also sells the Delco Remey Alternators. Extremely happy with mine. I kept my generator, but Alternator is the way to go.

Re: 12 V alternator choice
 

I prefer to use the original generator whether I'm running six or twelve volts . For brighter headlamps , the 55 wat halogen bulbs work well but need to be used with an alternator for good results . There are 25 or 35 watt halogen bulbs that can be used with original headlamp sockets but they aren't as bright as the 55 watt bulbs .

Re: 12 V alternator choice
 

The generator charges in amps and will charge a twelve volt battery quite well . The original starter works well . The original starter Bendix will work but many prefer to change to the modern style starter drive . Some feel that 12 volts slams the Bendix in to the flywheel ring gear harder and could be a problem . I have used both style starter drives on 12 volts and have never had a problem . The original Bendix drive MAY be easier to work with if a starter drive failed and needed to be changed on the road . All componets need to be in good condition . worn out parts will fail quicker after converting to 12 volts

Re: 12 V alternator choice
 

Run a shunt across your original ammeter so you don't burn it up with the increased current.

Charlie Stephens

Re: 12 V alternator choice
 

What size shunt? #12? #10? or?

Re: 12 V alternator choice
 

I use a regular (3 wire) 10 SI, maybe a 60 amp unit. All parts stores have them, but most don’t carry the one wire version of the 10 SI. They are more reliable and easily wired up. If a store doesn’t have the exact replacement you can re-clock any of the alternators just by taking out the bolts holding the housing halves and twisting one half to the position you want. One wire alternators often need the engine revved up before they start to charge. The regular three wire chargers start based on the voltage at wherever the exciter wire is connected, usually at the ignition switch accessory position if you are using a typical aftermarket switch.

Re: 12 V alternator choice