|
Doyle,
My comment was more about your assuming this owner to disassemble and diagnose the alternator. Sounds like he may not have the necessary electrical background (nothing personal Dralph12) . For example, in order to check the diodes, they must first be de-soldered so they can be individually inspected with a meter.
If it's faulty, and snce this is a rebuilt unit, the best course of action is to return it for a good one. If it's the regulator (maybe), do likewise.
As Tyson suggested, measuring voltage drop is a good test, but not many people know how to measure it. It isn't the same as measuring continuity with with an ohmmeter. The former is an active test under load, the latter is a static test for a continuous path but not necessarily a path able to support the load. A thin wire is continuous and an ohmmeter will indicate near zero resistance. However, if connected between battery and starter, then the circuit activated, it will surely fry, but if it somehow remains intact, will create excessive current resistance in the circuit due to it's size.
A voltage drop test measures voltage loss between two points. For example, to measure voltage drop between alternator and battery, use two long test leads, one at battery term. on solenoid (the alternator output wire is here) , the other at the + term. on battery. Engine ON, then observe the voltage drop (voltage loss via connections, broken conductor, etc.). Should be <.1 V or so. Test and observe under different engine speeds and temperatures.
For example, if source voltage = 12, and voltage drop test shows 12 volts, it's an open circuit; a reading of 6 volts indicates half of the available voltage is lost/not being used.
Hope this helps,
Sherwood
|