Re: replaced rectifier and it still is not charging.
Regulator/Rectifiers Tests
1. With all wires connected and the engine running at approximately 1500 RPM, check the DVA voltage from
each battery charge wire (typically Yellow wire) to engine ground. The two readings must be within 1.5 volts of
each other (i.e. if one is reading 20 volts, the other has to read between 18.5 and 21.5 volts). If the readings are
not equal, go to step 3. If they are equal, go to step 2.
2. Check DVA voltage from each of the Yellow wires to the Red wire going to the solenoid. The two readings
must be within 1.5 volts of each other. If the readings are unequal, go to step 3. If they are equal on both this
step and step 1, the regulator/rectifier and battery charging portion of the stator are good.
3. If the readings are unequal, place a mark across the connection between the stator and regulator/rectifier that
measured low. Turn the engine off and swap the stator leads. Crank the engine up and retest. The component
(stator or regulator/rectifier) that has the marked wire with the low reading is bad.
Alternate RR Procedure:
Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.
Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.
Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.
Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.
4. Disconnect the regulator?s Gray wire. At 800-1000 RPM, check the DVA voltage on the Gray wire FROM THE
REGULATOR measured to engine ground. The reading should be at least 8V DVA. If below 8V DVA, see
TACHOMETER TESTS below.
Regulator/Rectifier Bench Tests
1. Diode plate check:
With all wires disconnected from the regulator/rectifier, using a meter set on its Diode scale, test the diodes
from each of the two battery charge wires/terminals (typically Yellow wires/terminals) to the Red wire/terminal.
You should get a reading one way but not the other. Check the resistance from each of the Yellow
wires/terminals to case ground. You should have a high reading, typically in the M range. The Red
wire/terminal should not read to ground, but may show a very high reading (25M ohms or more).
2. Tachometer Circuit:
With all wires disconnected from the regulator/rectifier, check resistance between the Gray wire and engine
ground. You should read approximately 10K (10,000) ohms. Both (Gray to Red) and (Gray to each of the
Yellow) wires should be a high reading, typically in the M range.
Tachometer Tests
1. Disconnect the regulator?s Gray wire. At 800-1000 RPM, check the DVA voltage on the Gray wire FROM THE
REGULATOR measured to engine ground. The reading should be 8V+ DVA. If not, replace the regulator.
2. If at least 8V DVA, run a jumper wire from the Gray wire out of the harness to one of the stator?s Yellow wires.
3. If still no tachometer signal, try a known-good tachometer.
4. If still no tachometer signal, replace the stator.
If you don't have a DVA, you can order one here:
http://www.usatoolwarehouse.com/usatoolwarehouse/ESI-640.html
