[FC] thanks for help w/one-wire alternator...but

[Chris & Bill Strickland]

>Thanks to everyone who sent diagrams and links and info on alternator  
>conversion. I have an old casting, so I determined that "1"=F
>

It is okay to think that way in your head, but actually "1" is more like 
an on-off switch, turning the internal regulator "on"  and the regulator 
controls the field

>connected system puts out 12.85vdc at alternator/battery
>  
>

too low.  perhaps a bad diode trio inside the unit, perhaps something 
else -- reccomend taking it off and down to one of those parts houses 
that will check it for free (hoping to sell you something to fix your 
problem).  Probably causes your light problem, below:

>--->through all tests, the GEN dash light remains on and  bright<---
>

To what did you connect the dash light?

>also, since the disconnected alternator reads 7.5vdc, 
>
this reading is meaningless -- alternators are not like generators, and 
they are not designed to be run while disconnected from the battery.  
Where do you think that field current comes from, since it isn't from "1" ?

You have a pretty noticable voltage drop from the battery to the dash -- 
probably some connections there that could be cleaned up or improved -- 
it'd be nice to only have a half volt drop back to front., which sure 
would improve your headlight's lighting ability.

Now, this gets tricky if you're not on top of the game, but you can test 
the regulator yourself, on the car, connected, running -- there's 
probably a picture somewhere you could reference, but on the back of the 
Si series alternators, there is a small D-shaped hole. Poking a 
conductor (wire, small screwdriver)  a short way though this hole,  
grounding out a tab on the regulator to the case, will result in "full 
fielding" the alternator.  A distinct voltage spike would indicate the 
alt is probably still working, as it used to with your 18 volt readings. 
This really only tests the regulator, and not the diode trio.  The diode 
trio can be tested by removing it, and testing each diode (check your 
reference materials for diode testing, perhaps your digi multi meter 
instructions), but generally, if they are bad, they have a little melted 
spot in them which you can visually observe -- helps to know what a bad 
one looks like.  If the alternator isn't "alting", such as having a 
shorted winding, or bad brushes, or a bad diode trio, this test is also 
meaningless.  Also means you will learn how to hold the brushes back in 
the holder with a paper clip through the little holes so you can 
reaasemble it.  Remember to remove this wire!

Bill Strickland