voltage regulator

[hoganJr]

Hey this is my first post and I'm already looking for help. I bought a 79 XS400 from a guy I know. He and I and a couple others rode out of the Indianapolis area, over Niagara Falls and back home through Detroit/Windsor last summer so I know this bike is a runner. I bought it as a beginner for my 17 year old son. The main problem I have is the battery won't stay charged. The stator tests good. The rectifier tests good. The regulator is not like what the manual describes. It is a kind of a flat little sealed up thing with a green, brown, black connector. Can somebody tell me how to test this thing to know if it is good? If I start the bike and disconnect the regulator to measure the current at the battery do I risk anything but blown fuses? Would this be a valid regulator test?

Somebody ask an easy question so I can make a contribution to this website.

HoganJr

 

[Travis]

Use to a multimeter to test the voltage at the battery with it running at high idle with the regulator connected. Let us know what it reads. How are you testing the stator?

 

[hoganJr]

I am testing the stator exactly as it describes in the pages of the manual that I have attached. The numbers are all good.
When I clip the multimeter to the battery terminals and rev the engine it never shows more than like 10.24 volts.
Is this the information you need?

thanks

hoganJr

 

[hoganJr]

still learning to use the controls on this website and could not seem to edit my last post:
My regulator does not look like the one pictures in the manual. It looks like the pic I have attached.

Thanks again
hoganJr

 

[drewpy]

its a solid state reg. replacment is the only answer if everything else checks out

 

[hoganJr]

I've been going through all the connections and grounds looking for problems. Is it important for the regulator body to be grounded?

 

[drewpy]

try it, nothing to lose!

 

[hoganJr]

Travis and Drewpy, I found the place on the battery box where the reg mounts and I mounted it there. I found a ground wire coming out of the harness right near the battery box and I attached it to the frame. I made sure my battery had a good ground. With the motor reving over 4000 I was reading above 12 on my voltmeter. Kinda hard to get real accurate when you only got two hands, but definately 12+. So I'm excited. Not completely confident that all is good, but it looks hopeful.

Thanks

HoganJr

 

[drewpy]

good to hear

 

[Travis]

At that RPM, you should be higher than just 12.. Like 14 something.

 

[01ps]

Hey this is my first post and I'm already looking for help. I bought a 79 XS400 from a guy I know. He and I and a couple others rode out of the Indianapolis area, over Niagara Falls and back home through Detroit/Windsor last summer so I know this bike is a runner. I bought it as a beginner for my 17 year old son. The main problem I have is the battery won't stay charged. The stator tests good. The rectifier tests good. The regulator is not like what the manual describes. It is a kind of a flat little sealed up thing with a green, brown, black connector. Can somebody tell me how to test this thing to know if it is good? If I start the bike and disconnect the regulator to measure the current at the battery do I risk anything but blown fuses? Would this be a valid regulator test?

Somebody ask an easy question so I can make a contribution to this website.

HoganJr

If you need a new regulator I used one of these and it works great.

http://www.autopartswarehouse.com/d...rdQQVoltage_RegulatorQQ19811991QQSIVR125.html

Off a mid 80' Dodge pickup

 

[hoganJr]

thanks for the info...the link did not work, but I assume you mean the Standard Motor Products VR-125 you refer to in another of your posts. Good info, thanks again

hoganJr

 

[hoganJr]

I have been working on some other projects, motorcycle-related and otherwise lately but I returned to the XS400 last night. I got her started and began to disconect parts of the wiring harness to see if by diong so I could isolate some problem in the system that is causing the drain on the system.
I found that by disconnecting the brake/tail light my meter showed 14+ volts at 4-5000 rpms. Plugged in the voltage drops into the 12's. Then I realized that my brake lights are always on. I assume, from looking at the wiring diagram, that both bulbs serve as both tail and brake lights. I also am assuming that they are always on as opposed to never on because they seem bright. I disconnected the rear brake switch and removed the front brake lever. Both switches seem to operate correctly (the parts move freely).
That's where I had to quit for the night.
The plastic lense/box is broken and the top is gone on the tail light assembly. Is it possible that corrosion in the bulb sockets is causing both filaments to stay lit in the bulbs? Could that be causing a sufficiently excessive voltage drain to keep the battery from charging? Has anyone converted to a single brake/tail light to conserve power?

Thank you for reading this lengthy message.

hoganJr

 

[drewpy]

it could be that they are wired wrong? swap over the live wires and see what happens. other than that, a bum earth will cause all lamps to light as the juice finds its way to an earth point elsewhere in the loom.

 

[Drewcifer]

I'm hoping 01ps or someone that knows him can get him to draw up how this is done. I have the napa regulator and want to do the wires to the two terminals available on the napa part, just want to wire them up right.

Drewcifer

 

[elkriverscott]

If you need a new regulator I used one of these and it works great.

http://www.autopartswarehouse.com/d...rdQQVoltage_RegulatorQQ19811991QQSIVR125.html

Off a mid 80' Dodge pickup

2017 bought v 125 from advanced auto $21.00