help with putting an alternator on my A?

C

chopo

Senior Member
is this pretty straight forward? i think I need to use one of those gm 1 wire style? and lastly are there any spacer/brackets that need made? thanks for all your help.
 
6 volt? 12 volt? +or- ground? I used a 6 volt + ground Nu-Rex and it was a bolt on. :)
 
If you're buying one from a model a supplier it will come with the bracket needed. Other than that it's just a simple set up. Bolt on, then slide your wiring harness wires onto the post and tighten the nut down and it's done. Sometimes you do have to polarize them when first started for the first time. There will be about a 1 inch wide rubber cap in the back of the alternator on the top. Pop that cap off with a flat head, then you will see two little post sticking up. I believe it is the right post, but take your screwdriver and touch the post then touch the alternator housing with the screwdriver while it's still touching the post. This will start the charging. But you only have to do that if it's not charging upon initial start up.
 
Be aware if you are buying or have bought a 12 volt Pos ground alternator (one that has been modified internally to run on POS ground) that you can NOT just change the polarity of the battery to make it NEG ground.

You must get a NEG ground alternator for a neg ground car. The wiring inside the alt is changed to change the polarity.

Using the wrong polarity will smoke the alternator ... unless someone has comeup with an alternator that can be changed with jumpers or some similar method.

One wire alternators do not need to be polarized. Polarizing applies to generators.

One wire alternators will not charge until the engine speed reaches a point above idle ... after it starts charging it will continue to charge at an idle. After the engine is stopped you must rev up the engine each time to get it to charge.
 
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I got tired of rebuilding my 6 volt model A generators every year. Whats more is I had to change my charging rates for winter driving or for summer driving because of using the headlights more during the winter months. Now I have Mac's new 6 volt positive ground alternators on both our Tudor and our Standard Phaeton. I am not sorry that I changed them over. The alternators automatically adjust the charging rate that your battery requires. You can also use those new brighter 6 volt Halogen headlight bulbs now too. The same fan belt fits both and there is nothing different in the mounting of the alternator except for the brackets that come shipped with the new alternators.
 
chopo said:
i think what i need to see is how they attach to engine
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Chopo, just find 2 shackle bars and use them to attach the alternator. One end of each goes under the bolt at the engine and the alternator slips between the other end with a bolt through them. You may have to enlarge the hole in the end at the motor.
 
James Rogers said:
Chopo, just find 2 shackle bars and use them to attach the alternator. One end of each goes under the bolt at the engine and the alternator slips between the other end with a bolt through them. You may have to enlarge the hole in the end at the motor.
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thats what im after... thanks and it will be 12 volt neg ground
thanks
 
Logan said:
If you're buying one from a model a supplier it will come with the bracket needed. Other than that it's just a simple set up. Bolt on, then slide your wiring harness wires onto the post and tighten the nut down and it's done. Sometimes you do have to polarize them when first started for the first time. There will be about a 1 inch wide rubber cap in the back of the alternator on the top. Pop that cap off with a flat head, then you will see two little post sticking up. I believe it is the right post, but take your screwdriver and touch the post then touch the alternator housing with the screwdriver while it's still touching the post. This will start the charging. But you only have to do that if it's not charging upon initial start up.
Click to expand...


that is a good way to short out your alternator. I have never polarized an alternator before
 
Never try to polarize an alternator. It is not designed to be, and should produce the correct voltage at the time of installation. That is what the internal regulator is for.
 
The one wire alternators are fine, but you can take a standard GM10SI or 12SI alternator with a DA Plug from NAPA or other auto parts store. Connect the red wire from DA plug which goes to F (Field) inside the alternator to the Hot wire on the alternator. Connect the white wire from the DA plug to a 3A/100V diode cathode side (Bar on the diode marking). Connect the Anode side (top of wedge on diode symbol)of the diode to the hot side of the coil with about 2 to 3 ft of wire. Put heat sink tubing over the diode to prevent shorts. You must use a fuse with this set up as the Field of the alternator draws current when the car is not running. You must pull the fuse when you stop the car or have a full electrical cut off. If you want some more info on this send me an email jrelliott42@gmail.com
 
I am in the process of converting back to 6V from a 12V alternator. Found the correct Power House Gen and want it more close to original. If you are interested in the parts, let me know. email address jrelliott42@gmail.com
 
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