Voltage Regulator?

[DenzComp]

Hey-

I went out on the bike today('78xs1100) and it started to sputter then completely die. Battery was completely drained.

I had this problem before and thought I had it solved...I ended up getting a stator from andreas. The bike had a new battery, but just to be safe I went out and bought another one. Put everything on and THOUGHT it was fixed.

WRONG.

It did the same exact thing....My next best guess is the Voltage Regulator. Would this cause my batteries to die? I popped the tank off and removed it. My voltmeter is lent out right now...I'm probably just going to go ahead and try to get a regulator because I don't know what else it could be....

Any input would be greatly appreciated.


Thanks,
-Dennis

[DenzComp]

I don't know if this has anything to do with it...but I saw something about the TACH in a post while searching.

My TACH needle has been bouncy since I purchased the bike a few months ago. You could tell where it should be...about the middle of the bounce...

[DiverRay]

Dennis,
Before you spend more money, check the wire connectors BEHIND the fuse block. It takes three screws to be able to move the metal plate, and get to the wires. E.Liberty had a charge problem with his '79, and it was the connections. you could see the burnt connectors and wires. I had the proper connectors from Geezer, and cut and installed a new connector onto his bike. He's had no electrical problems since.
If the wires do look GOOD, then I would spring for the reg/rec. from Geezer. It works better than a new dealer item, and has a lifetime warranty!

[DenzComp]

Do those connections have anything to do with the fuse block itself?

Th guy I bought it from has the fuse box bypassed and individual fuses wired in.

I've had that plate off before when I switched stators. I'll look again later when the voltmeter gets here.

What's the easiest way to test the regulator?

[DiverRay]

Go here, and it will help. This is Geezers web site.
http://www.oregonmotorcycleparts.com/index.html

[jeffe]

Just a thought and a shameless plug for Geezer. Even if you reg/rec is good , it is worth the price for his replacement. It will give a very noticable improvement in your charging power. This is a big deal on these bikes. Yamaha got just about every thing right except the charging output.

[DenzComp]

Volt meter got here. I checked the resistance...using the "chart" in the Clymer manual.

I got all my readings...wrote them down...

Then I switched the leads and went through and tested again.

I wasn't getting a reading...I was...but it was 0.

For example...b1 and b2 one way was say...1.1 then when switching leads it was 0.

It said the reading would be lower one way and higher the other if it was bad...0 is lower I guess...

[DenzComp]

Can anyone tell me if that would point to it being bad?

I'm pretty sure I tested it right...but just want to be sure before I get a new one.

[DiverRay]

Just have a look at Geezers site, oregonmotorcycleparts.com, and you should have an answer. He has a section there that tells you how to check the system.
Tony is very helpful to everyone here, and a great electronic guy.

[DenzComp]

I just did the test from Geezer's site, but I have no idea what the readings mean...

With the POSITIVE of the voltmeter to the POSITIVE of the REC I get a reading of 0 on all the whites.

With the NEGATIVE of the voltmeter to the POSITIVE of the REC I get 1.243 1.238 and 1.223

With the POSITIVE of the voltmeter to the NEGATIVE of the REC I get .960 1.207 and .990

With the NEGATIVE of the voltmeter to the NEGATIVE of the REC I get all 0's.

[rman]

Diode scale

Denzcomp,

If you have a voltmeter it should have a diode scale on it. It looks like a triangle with a “T” bisecting it. Put the meter on this scale.
Place your red lead on one of the white wires from the rectifier and the black lead on the red wire. You should be getting a reading from each of the white wires to the red wire.

Place the black lead on the white wires and the red lead on the red wire from the rectifier. You should show OL on your meter or “Open Load” for all the white wires to the red wire.

If you have all this then so far so good.
Now with the black lead on the white wires place the red lead on the black wire from the rectifier. You should show a reading. Swapping the leads again. Red lead to white wires black lead to the black wire from the rectifier and you should get OL.

If you get all this then the rectifier is good. Not sure about the regulator portion.

I do not remember the exact reading that you will get something between .6 and 1.7 would be my best guess but what the reading is IS less important then getting a reading verses an OL.

[DenzComp]

Okay...

With the red lead of the voltmeter to the positive of the rec and the black to the whites...I get all .0L

With the black lead to the positive of the rec I get
.523 .527 .536

With the black lead to the negative of the rec I and the red lead to the whites I get all .0L

With the Red lead to the negative of the rec and the black to the whites I get.. .511 .524 .507

I still have no ideas what these numbers mean...is my rectifier fine?

[DenzComp]

If anyone can tell me if it's bad or not I'd really appreciate it. I don't want to place an order until I know for sure.

I'm getting the readings that I posted...I just have no idea how to interpret it...

I'd like to get back on the open road ASAP...riding season will be over here soon in NY.

So if anyone can tell me if it needs to be replaced based on the reading I got I would truly appreciate it.


Thanks,
-Dennis

[TopCatGr58]

Hey Denz,

I'm no Electrical Guru, that's Geezer and Randy's job!

From what I can gleen from the manual and your readings, it sounds like the RECT might be okay!? The REG is just supposed to divert the charging voltage to ground when it gets above 15 volts! The manual states that the readings for the rect should be different by a factor of 10 when measured one way vs. the other! And it states to use the Ohmeter, not the diode setting of the voltmeter.

However, a reading of "0" ohms is a reading of a direct no resistance wire/circuit. SO...the readings may in fact be bad if you aren't getting readings like 0.01 in one direction and 0.10 in the other=factor of 10!?

But again, best to PM/email Geezer or Randy for proper clarification, or info on other tests/measurements!
T.C.

[rman]

DenzComp,

Based upon the reading you just gave me your rectifier is good. A rectifier circuit is simply a diode bridge arranged to let positive AC alterations flow in one direction and negative alterations flow in a different direction. That is what you have proven by using the diode scale on your meter.

I have been working in the electronics field for the last 15+ years. And I know what a bridge rectifier is.