Help me test my rectifier

Could use some help here. My manual says to set my ohm meter to X1 for one test and to X1k for the other test. My multimeter doesn't have those settings. But I'm still pretty sure my rectifier is toast.

Am I right that my meter is basically always in x1 mode and that the numbers are just the range up to which it will read?



For the first test (+ -> yellow, - -> black) I had to set the meter all the way up to the 2000k range to get a reading. And those readings were around 1200 for both yellow leads. That seems way more than 20 ohms.

For the second test (+ -> black, - -> yellow) I had to set it in the 200k range and both read about 160. I'm a little less clear on how to read that. Should I be interpreting that as 160k?

It seems like the rectifier has failed the first test, but passed the second. Is that correct?

For the first test you have to set to the lowest value = 2000 Ohm = 0 - 2000 Ohm
For the second test set to 200 kOhm = 0 - 200 kOhm

What's the output?
Steve

Scirocco wrote: For the first test you have to set to the lowest value = 2000 Ohm = 0 - 2000 Ohm
For the second test set to 200 kOhm = 0 - 200 kOhm

That's what I did for the second test and it read about 160. I assume that means 160k and that it passed that test.

For the first test, When I set the multimeter to the lowest range (2000) and measured, I got no reading, it just said 1. I tried stepping up through the ranges on the multimeter and I didn't get a reading until I got all the way up to 2000k. At 2000k the readings were about 1200 for each yellow lead. The test in the manual says that needs to be less than 20 ohms. So assuming I'm using the meter correctly (which I guess is my question here), the rectifier failed the first test.

Swest wrote: What's the output?

You mean what's the output of the rectifier when charging? I'm not getting any charging. Working with a fresh battery, voltage is about 12.6 measured at the battery terminals and it doesn't change when I rev the bike.

Have you tested the output of the stator?
Steve

SWest wrote: Have you tested the output of the stator?
Steve

Not yet. Rectifier was easier to get to. I should have time to pull the side cover and test the stator tomorrow.

But I'm hoping for confirmation that I'm doing this test correctly so I'll know whether or not the rectifier is toast.

It appears you are though I like to start at the source. I believe my numbers are down due to weak 40 year old magnets. Enough to keep the battery up and get to 14.5 v after HWY speeds for a while.
Steve

SWest wrote: It appears you are though I like to start at the source. I believe my numbers are down due to weak 40 year old magnets. Enough to keep the battery up and get to 14.5 v after HWY speeds for a while.
Steve

Yeah, I wasn't really able to warm the bike up when testing the voltage at the battery today. That was just right after starting, still had to have a bit of choke to keep it running. 12.6 volts at "idle' (or pretty close to idle) and it didn't raise a blip when I revved it up to 4k rpm.

I'd check the stator voltage then go from there.
Steve

A 1 on the display say out of range and you have to go to the next higher range.
If your readings for the first test is more than 20 Ω (1600 at 2000 kΩ) the diodes in the rectifier are shot.
They do the opposite job as for the second test and your rectifier/regulator unit will never fully charge your battery.
13,5 - 14,5 Volt is a must have at 4000 rpm. The stator only readings should 30-40 Volt and higher.
I would say buy a new rectifier/regulator unit if your stator output is in spec.

You have to use this setting for stator test, AC Voltage

Stator checked out OK. I tested its output without even warming up the bike and it was reading 70+ at 4k rpm (manual says "about 75"). Time for a new regulator/rectifier.

I'm seeing a pretty wide variety of prices on ebay for replacements. Is this a case where it's worth paying more? Or is a rectifier pretty much a rectifier?

This one is $30.

And this one is $120.

No eBay APP ID and/or Cert ID defined in Kunena configurationI have my eye on this one. For a three phase system and one Ness suggests. Can't find used ones but the price is right.
Steve