What type of alternator is this on my 40 Ford.

[Bazooka Joe]

Originally Posted by 51504bat

Recommend Newport Wipers for your conversion. JMO
https://newportwipers.com/product/1940-ford/#switches

That’s outstanding! I purchased one from Bob Drake couple months ago, a two speed. Similar price..

Thankx for the site..

[Bazooka Joe]

Originally Posted by joe 1950

the numbers are on the top of the case that bolts to the front housing right behind the adj. bolt i could see it on the one picture you sent but it was upside down and couldn’t get my pewter to lock in to see it but if you have it working by cleaning the terminal great easy fix

Says something to the effect

1102430? 61A
6M1 or I-12VNEG

Taking it 61 amprege..

Thank You for where to look……for the digits…..

[petehoovie]

Originally Posted by Bazooka Joe

Says something to the effect

110243? 61A
6M1 or I-12VNEG

Taking it 61 amprege..

Thank You for where to look……for the digits…..

[markdtn]

Originally Posted by cas3

Well, after Allens response, I'll try to help. It looks like the common 10 SI, that should be stamped on the case near the volts/amp rating. The white wire looped around to the power post makes it a one wire alt. The black wire will go to battery, but should be switched so it will not run the ignition off the alt after you turn off the key. Originally, that white wire went to the idiot light in the dash. Some folks wire it that way so you don't have to bring up RPM's to trigger it to start charging. There are a few different ways to wire the 10 SI, a google search will bring up diagrams.

No idea what the home made black box is, you'll have to trace the wires to figger out what they had in mind.

I don't think that is wired as a 1-wire? The plug right side (#2) on a 10 or 12 si usually goes to a common block where power is pulled from but many Oldsmobiles are wired like this with the power right to the output post. The left wire (#1) in the plug should go to an "idiot light" to tell if it is charging or not.

PS-many times you can make those alternators go again with a brush kit from Evilbay or the Jungle site. They are not hard to "rebuild".