Re: Is there a way to test a rectifier?
There is a way, but nobody has said it yet. So, here goes, do it exactly like this:
First off, I don't know which rectifier your motor has. Let's assume it has two yellow wires and one red one. You need a multimeter (ohm meter) or a battery powered circuit tester (continuity light). Many digital multimeters won't work unless it has a diode test function. Best kind is an analog meter, with a moving hand.
EDIT: You asked about a RECTIFIER, so I assumed you mean a stand-alone rectifier. If your motor has a RECTIFIER/REGULATOR combined unit, the following tests do not apply.
1. Disconnect all rectifier leads
2. Connect your meter's black test lead to a yellow wire and the red test lead to the red wire, and check the resistance reading. It should show either a high or low resistance.
3. Now reverse you test leads to the same yellow and red wires. If you got a high resistance before, you should get a low resistance now, and vise-versa. If you get these results with both tests, THAT diode is good. If you got either a high or low resistance on BOTH tests, THAT diode is shot.
4. Now repeat both tests on the other yellow wire and red wire. You should get the same results, good or bad.
5. Repeat on third yellow wire, if there are three.
6. You aren't done yet. Now you need to repeat all the tests, connecting your meter's test leads to a yellow wire and ground (metal rectifier housing or black wire, whichever applies)
7. Repeat with each other yellow wire and ground.
There are four diodes in a two-yellow wire rectifier and six diodes in a three-yellow wire rectifier. There are two tests for each diode. That means a total of either eight or twelve tests, and it must pass all of them. Fail just one, and the rectifier is shot.
