Re: How to test if battery is being charged?
not sure how many or what color wires you have on your reg/rec and stator but i just went through all this on my motorcycle and here is some info that hellped me on testing these units which i believe should operate the same way on an outboard charging sytem the voltage and ohms reding may be different though but should give you a good idea how to test and what you are looking for
TESTING THE REGULATOR/ RECTIFIER UNIT
DIODES
The unit contains a set of 6 diodes. These are what we are going to test first. Diodes are like one way check valves for electricity. It will only allow the current to move in one direction. This is how it transforms ac voltage into dc voltage. The particulars of that do not matter to us though.
Set the meter to measure ohms. Place the red lead from the meter on the first stator lead (s1) and the black lead on the BCL. You should get a reading. Record it. Move the red lead to the second stator lead (s2) and keep the black on the bcl. Again , you should get a reading. Do the same with s3. All three of the readings should be very close. The actual value is going to depend on which init you have. Reverse the red and black leads and do the same three tests again. You should get OL or no reading on all three. If you do get a reading then the diode is bad. Therefore the whole unit is bad.
To test the ground side diodes, place the red lead on the ground wire and the black on s1, s2, and s3 respectively. You should once again get a reading on all three, and the readings should be close together. Reverse the red and black leads and repeat the test and all three should be OL or have no reading. Again, if you get a resistance, then there is continuity where there should not be and the unit is bad. I usually make a little chart
TESTING THE STATOR
The stator is an AC producing coil. It can and should be tested in three ways. They are resistance, output, and insulation breakdown.
RESISTANCE
Disconnect the three yellow wires coming from the stator. (If you are still using the stock plug, double check the wiring and terminals. These have been known to get hot then get brittle and the insulation starts to chip leading to a short.) We are going to call these three stator wires s1, s2, and s3. It does not matter which one is which. Set the multimeter to read ohms. Use one end of the meter on s1 and the other on s2. Record your reading. Do the same thing between s1 and s3, and then s2 and s3. You want to get a reading of very close to .2 ohms. Much higher and there is likely a partial break in the wires. The stator is going or is already bad. No reading or an open line between any two leads would indicate a complete break in the wires and the stator is bad.
OUTPUT
To test the output off the stator, we are going to leave the three yellow wires disconnected. The meter is going to be set to volts AC. Use the red probe of the meter on one of the yellow leads. The black probe of the meter is going to go to ground. Start the engine and watch the meter. It should read about 14-18 Vac. This number will increase significantly with the engines rpms. It should rise to 50-60 volts depending on rpms. Repeat this process with each of the yellow leads. In effect we are going to do three tests. If any of the leads do not put out enough AC voltage, then the coil is bad. Replace the stator.
INSULATION BREAKDOWN
To check for insulation breakdown, we are going to set the meter to measure ohms. You can use the continuity setting if your meter has it. Use one probe of the meter on one of the three yellow leads from the stator. The other meter probe goes to ground. If the stator is out of the bike, then this lead would go the metal core of the stator. The meter should read OL or open line, or show no continuity depending on the meter. If it does give a reading, then the coil is shorting to ground and the stator is bad. Repeat this for each off the yellow wires. If any one is bad, the entire unit needs to be replaced.
