OLD TIMEY electronics tester has no DIODE TESTER?

[scootertramp]

I wish to test the diodes in my RR so I removed it and I have it setting in front of me..  I have an older model tester. How Do I set the multi tester to properly test the Diode. I put it on OHMS and used the OHM (battery inside)probe and put the Ohm probe on ALL THREE  white leads (one at the time)and put the other end on the red out put wire. I got a small regular (2 units?)reading on every white wire and no readings at all on the brown or black wire.. No reading at all the OPPOSITE way.. so how do I know its good? am I getting continuity? that is a reading all the way through? what do I want to see? My multi-tester is very old.. but works.. thanks for all the help..

[Brian Moffet]

I'm going to refer to a variety of wires here.  Red wire, Black Wire, White Wire all refers to your R/R.  Positive Wire, Ground Wire is on your Ohm Meter/Volt Meter.

Okay, so you can actually see some result from putting the ground wire on the white wires, and the positive wire on your red wire.  You are not seeing anything when you swap the wires from the ohmmeter.  This is good.  It means you have continuity from the white wires to the red wire, but not the other way around.

Now, Connect the ground wire to the the black wire on the regulator. The positive wire from the ohm meter to each white wire on the R/R.  You should see a similar reading as you saw from the first test.  If you flip them, positive wire on the black R/R wire, and ground on the white wires, you should see nothing.  This establishes continuity from the black wire to the white wires, but not from white to black on the R/R.

If this is the case, the diodes are good.

Ignore the brown wire coming from the R/R for this test.

Brian

[Lucky]

One other note:

A diode can be bad in 2 ways: Open (no continuity), Shorted (complete continuity)

when testing the diodes this way, you should see SOME resistance (1.5 Ohms) on the continuity side.  this will differ from complete continuity on your tester. (just like touching the 2 leads together)

--Lucky

[scootertramp]

 DID the test both ways.. It's NOTICABLY MORE when I touch the tester leads together than when I do the check on the RR.. there seems to be less current coming through the RR than when I have the tester leads together,?Is this indicative of a good unit? so that would be "some" resistance? thanks..

[Lucky]

YUP