Full field alternator test?

[1BAD68]

I have a single field alternator on my 68, I started the engine and grounded the field terminal at alternator and checked voltage at battery, voltage didnt change (stayed around 12.3 v)
I'm assuming my alternators bad but want to double check with someone that knows this stuff better than me.

[Nacho-RT74]

the field prong on single field must be feeded with positive. Negative is already feeded by the other brush directly bolted on to alt back housing without prong and isolator.

[Plumcrazy]

the field prong on single field must be feeded with positive. Negative is already feeded by the other brush directly bolted on to alt back housing without prong and isolator.

  Run a wire from the positive battery terminal to the alt field wire.  Make the connection at the battery first because when you make the connection at the alternator there will be a spark. 

You don't want to create sparks at the battery. 

[histoy]

Can't you do the same test by using a jumper from the hot wire on the alternator over to the field terminal?

[Nacho-RT74]

as far some problem it could exist that I still don't know... yes you can do it.

[Plumcrazy]

Can't you do the same test by using a jumper from the hot wire on the alternator over to the field terminal?

That would work also.  But whenever I'm jumping voltage or ground to something, I prefer to go to the negative or positive battery terminals to eliminate any other wiring.

[1BAD68]

thanks for the advice, I did it and it didnt full charge so I took it to a alternator shop and they tested it, it was only putting out barely 20 amps.
He said to rebuild it would be just under 100 bucks, so I hope to be picking it up sometime next week.

I want to go ahead and replace the voltage regulator also, can anyone recommend a reliable unit?

[Plumcrazy]

I want to go ahead and replace the voltage regulator also, can anyone recommend a reliable unit?

I would buy one like this one. http://www.4secondsflat.com/regulator_tech.html

[1BAD68]

I want to go ahead and replace the voltage regulator also, can anyone recommend a reliable unit?

I would buy one like this one. http://www.4secondsflat.com/regulator_tech.html

I went to Auto Zone and bought this one for $14.00
I pulled the cover to look inside and it looks like the one in the link and it looks like my old style cover will fit on there.

[1BAD68]

I went back and checked my old alternator because I thought it was date coded, but it must have been replaced years ago because there was no date code on it, so I ordered one from the Zone for 37 bucks. I cant see spending 100 bucks for my old one to get rebuilt.

[Nacho-RT74]

you could rebuild and upgrade with more output with:
http://store.alternatorparts.com/index.asp?PageAction=VIEWCATS&Category=55

your one is old style round back.