Testing rectifier according to factory manual

[fbody_mike]

Ok, I've found errors in factory manuals before, but I'm starting to think I'm losing it.

I was testing the charging system on my old XJ650 Yamaha which is fairly different than the GS but still has a three phase rectifier. I noticed the manual shows the volt meter on resistance and placing the positive probe on the cathode side of diode, the negative probe on the anode and showing there to be continuity. This is opposite for how to forward bias a diode.

I figure Yamaha just got it backwards by accident. But then I checked my gs250t and gs450 and gs550e manuals and found the same error.

Were the Japanese meters backwards? Has anyone noticed this? Do I need a nap? I even broke out my old Triplett and Calrad analog VOMs, I still think these manuals are wrong.

[Brendan W]

Never gave that too much thought. Just figured as long it's effectively open one way and has the required resistance the other way.

[Steve]

To check the diodes, you need to check in both directions. One direction will check for opens, the other direction will check for shorts.

There are six diodes in the rectifier, which means there will be twelve measurements. If any one of them is bad, the entire rectifier is bad.

.

[posplayr]

https://www.fluke.com/en-us/learn/best-practices/test-tools-basics/digital-multimeters/how-to-test-diodes-using-a-digital-multimeter

sounds like manuals are wrong for Fluke meters.

[Gorminrider]

Here: if you want confusion, trust Honda!- note the "note".

test_hondarectifier.jpg

[fbody_mike]

Oh, that Honda note makes sense. I will have to keep an eye out for a older Japanese VOM, interesting.

[Gorminrider]

well, I just do as Steve said but it doesn't tell you much...and DO see this thread just bbelow,
Thread: Charging system hasn't failed, should I mess with it?

page 2 and 3 of this thread https://www.thegsresources.com/_foru...67#post2576867

where I posted three different R/R diagrams...

AND in any case, You can't easily bench-test the voltage regulation circuit. SOooo, the best way is to hook the R/R into a bike or just Possibly, comparing diode direction readings with the same model of a "known good" one might tell you if the rectifier is blown but again, tells you nothing about the regulation circuit.

[posplayr]

Never mind the point that most series r/r use dynamic rectification where there is no diode

[Gorminrider]

hmm, Yes, these Series type are using SCRs as rectifiers, aren't they? I haven't aquired a diagram for them yet.

I've tried to make setups to test regulation ...cheapo tin aligator clips snaking all over ..it was just an exercise in frustration at my "paygrade" .

[posplayr]

hmm, Yes, these Series type are using SCRs as rectifiers, aren't they? I haven't aquired a diagram for them yet.

I've tried to make setups to test regulation ...cheapo tin aligator clips snaking all over ..it was just an exercise in frustration at my "paygrade" .

dynamic rectification uses FET with timing to emulate a diode.