Reg/Rect: Quick ?

[corey]

Again, I'm having electrical problems. I've read the post on here, and (I think) I know what I'm doing. My reg/rect unit has me confused a bit though. The three prong connector coming from the unit only has two wires on it: green and brown. The black one is missing?! The connector it plugs into has the black wire, and the Clymer's book shows the unit having three wires... so where's the last one?

[Geezer]

The black ground wire was reduntant and left off all but the earliest ones.

Let me know if you need help testing the reg, rec unit.

Geezer

[TopCatGr58]

Corey,

As Geezer said, was redundant, they use the reg/rect case to frame as ground, so just make sure where it contacts the frame are clean, along with the bolts!
T.C.

[Geezer]

Originally posted by TopCatGr58
Corey,

As Geezer said, was redundant, they use the reg/rect case to frame as ground, so just make sure where it contacts the frame are clean, along with the bolts!
T.C.

It also grounds through the black wire in the other plug...

Geezer

[corey]

Thanks to both of you!

Geezer: could you run down the reg/rect testing procedure for me? I tested it according to the book, but my readings showed up weird. I talked to TC about this in another post. With the leads set one way, I received readings of about 2 or 3 ohms (or k ohms, can't remember). When the leads were reversed, I couldn't get a reading. I'm assuming right now its because I'm using a digital gauge.

Comments?

[Geezer]

I wrote up rectifier testing instructions and posted them here; http://www.oregonmotorcycleparts.com/FAQ.html

Unplug the 6-prong gang plug and test the red wire both ways to the white wires and then the black wire to the white wires.

Either use a battery powered test light or add a single flashlight battery into the circuit and set the meter on a low voltage DC scale. It is more important that the power flows one way and not the other than what any of the numbers are.

The way to test the voltage regulator is to turn on the ignition but don't start the engine. Lay a .002" feeler gauge along the side of the alternator and if all is OK, the gauge will be drawn the engine when you pull it away.

Geezer

[corey]

I tried the feeler gauge test, but with a paperclip. It wouldn't even pull the thing toward it at 1/10 of an inch or so. I then took the cover off and the magnetic rotor would still only only barely hold on to the clip. That indicates a bad regulator and not a bad rotor?

[prometheus578]

Just stole this from the "Yamah Triples" site. Seems to make sense. Any electrical gurus want to comment on it for me?

Charging System made Simple

Charging problems aren't always the regulator, they can be caused by something as simple as a shorted wire. It's pretty easy to test, despite the directions in the service manual.
The alternator depends on the battery providing current through a field coil to produce a magnetic field. One end of the coil is connected through the ign. switch to the battery and the other end goes to the regulator, which acts as a variable resistor between the end of the coil and ground. The resistor, a power transistor, goes to it's lowest value to allow the most current to flow and produce the most output when at idle or with heavy loads. When less output is needed, like when the revs are higher, the resistance is higher, allowing less current flow through the field coil. If the end of the coil is grounded by a short it will cause the alternator to produce full output all the time.

Using a digital voltmeter, measure the battery voltage. It should be about 12.5 volts and drop to about 12.0 with the switch on. Start the bike but keep the revs low and don't go over 2000 rpms. As you rev up the engine the voltage should increase until it's about 14.0-14.5 volts at 2000 rpms. If you rev it up a bit more, the voltage should stay the same and go no higher. If it still keeps going up the regulator is bad or the end of the field coil is shorted to ground. (Don't go any higher than 15-16 volts, don't want to cause anymore damage.) Unplug the connector to the field and measure from each pin to ground to make sure neither is shorted. If that's OK then replace the regulator.

If the voltage stays at 12.0 volts and doesn't go up when the engine is rev'ed up, then either the regulator or the alternator can be bad. Measure the coil resistances with the digital meter to see if they are in spec. and if not, replace the alternator. If the coils test OK, try grounding the non battery end of the field coil with a jumper clip, start the bike and see if the voltage goes up when you rev up the engine. It should go up as speed increases 'till you reach 14.5 volts at 2000 rpms. Stop there because the alternator is good and the regulator is bad or the wiring is broken or has burned up connections somewhere.

[Geezer]

It could be either but a paper clip doesn’t work as well as a feeler gauge.

You can also unplug the field coil and test for battery voltage across green and brown wires. Battery voltage = good and much less than battery voltage is bad.

Also check the resistance on the field coil.

Geezer

[skids]

The rotor is that thing that spins to move the magnetic field back and forth. It is just metal and nothing to wear out. The field coil is the black cylindrical ring and it gets it current from the volt regulator. If you have no strong magnetic field (with the key on, bike does not need to run) , then either the volt regulator is bad, the connectors to it are bad, or the field coil is amiss. I had a field coil go bad as the insulation in its wires cooked and caused a short to its case. As I remember it, its short was where the wires connect the field coil AT the field coil. I am told that it is somewhat rare.

Originally posted by corey
I tried the feeler gauge test, but with a paperclip. It wouldn't even pull the thing toward it at 1/10 of an inch or so. I then took the cover off and the magnetic rotor would still only only barely hold on to the clip. That indicates a bad regulator and not a bad rotor?

[Geezer]

Originally posted by skids
The rotor is that thing that spins to move the magnetic field back and forth. It is just metal and nothing to wear out. The field coil is the black cylindrical ring and it gets it current from the volt regulator.

You are correct on this. I help a lot of people with charging system problems and some times I forget which bikes use what.

Geezer

[randy]

Corey, are you sure you're not charging? What points you toward a regulator problem?

Have you run the bike with a meter on the battery leads? Should show about 14volts dc at 2500-3000 RPM. If not, then I'd say you had a regulator problem.

[corey]

Randy: The bike charges enough to keep the battery up, just not enough to keep the headlight/accessory lights from dimming. To be honest, I didn't realize it wasn't charging to full capacity until I tested the voltage on the battery with the engine running. With the biked revved at about 2500-3000 rpm the battery only read 13.1something volts. Supposed to be higher, no?

I took the alternator apart and inspected things. I took the stator (I guess that's what it is, sits in the middle of the entire unit, inside the rotor [?the part that spins?]) off and all the wire connections looked okay. I noticed some weird accumlation of blackish stuff on some of the parts, as well as a little chipped part along the ribs that are part of the coil. Didn't figure it would be anything detrimental. Man, I hope I'm using the right terminology! :S

I bought an analog guage today, as I heard the digitals kinda mess with readings while testing the regulator. I'll try it again soon (hopefully tonite) and get back to everyone.

[randy]

While you're at it, check three things:

Dirty connections

Dirty connections

Dirty connections

Especially the plugs behind the fuse box mounting plate. Well hidden and often overlooked!

[skids]

Originally posted by corey
Randy: The bike charges enough to keep the battery up, just not enough to keep the headlight/accessory lights from dimming. To be honest, I didn't realize it wasn't charging to full capacity until I tested the voltage on the battery with the engine running. With the biked revved at about 2500-3000 rpm the battery only read 13.1something volts. Supposed to be higher, no?

I took the alternator apart and inspected things. I took the stator (I guess that's what it is, sits in the middle of the entire unit, inside the rotor [?the part that spins?]) off and all the wire connections looked okay. I noticed some weird accumlation of blackish stuff on some of the parts, as well as a little chipped part along the ribs that are part of the coil. Didn't figure it would be anything detrimental. Man, I hope I'm using the right terminology! :S

I bought an analog guage today, as I heard the digitals kinda mess with readings while testing the regulator. I'll try it again soon (hopefully tonite) and get back to everyone.