[FC] ALTERNATOR TEST my 2 cents

[N2VZD at aol.com]

My bench testing of internal regulated alternators is done with a small  
test harness I made. I have @6 inch red wire with a clip on it from the 
battery  connection on the 2 pin plug (closest to back of vehicle) and a wire from 
there  thru a 57 bulb to the other terminal. I hook 12 volt battery to the 
red terminal  and negative to the case. I hook the clip to the positive 
terminal. The light  bulb should light until I spin the alternator. It goes out 
quickly when I spin  it with just an impact driver on the fan nut. This at 
least tells me it is  putting out , not how much etc. This is not precise 
test , but tells a lot when  I am running my motors on the bench for the first 
time, or rebuilding an  alternator. I have not had one yet that had a charge 
problem when installed in  the vehicle after this test.
 I just did one yesterday on the bench.  
    By the way , around here , the GM internal regulated  10SI? are getting 
harder to find , and the new rotors have gone way up in price  suddenly. I 
put these on all the motors I build. I just went 40 miles away to  pick up 6 
cores yesterday after doing a phone search. 
If needed , I will take a picture of my cob job test unit. VERY simple to  
make. It may already be on the net somewhere.
Regards, Tim Colson     http://www.cnycorvair.com/Little_Corvair_Shop.php