Issue with RR or stator?

[oldbikerdude]

Rode to Stratford yesterday for last bike meet of the season, rode there with no issues, when
leaving a few hours later, engine started no problem, but no dash lights on, rear right turn signal lamp is on. (This is the single filament bulb, should only operate when turn signal on).
Voltage meter showing very low voltage, as in not charging.
Got home without issue but was worried I may run out of battery juice before I got home.
This morning bike starts up no problem and then started the electrical checks on the battery, stator and RR.
Followed the manual for checks, here's what I found.

Battery (with ign switch on) - 12.25 V ( a bit low but with engine running 14.25), assuming here my stator is good.
Regulator red/white to ground - 12.22V DC
Stator 6 Pin connector black to white - 10.8 V DC ( should be 8-10V)

Next check says to check AC voltage between between 2 Yellow leads and then the 3rd yellow wire.
Is this check supposed to be done with ignition switch in the on position and engine not running, or should the check be done with the engine running?
I get 0, 0 ,0 with ignition on, but get 12.3, 12.48, 12.5 VAC with engine running.
Manual states should be seeing 8-10V.
Not sure what this means. Stator bad, starting to go bad?

Next was stator continuity check
6 Pin stator connector black to white 12.5 ohms (should be 10-12 ohms)
Y1 to Y2 - 0.4 ohms (spec is 0.4-0.5)
Y1 to Y3 - 0.5 ohms ( spec is 0.4-0.5)
Y2 to Y3 - 0.4 ohms (spec is 0.4-0.5)
Each Yellow wire to ground - infinite
Looks like everything checks out OK here.

Checked the Rectifier next, here's what I found.
Red/white to green - infinite resistance (spec is 0.5-50 ohms)
RW to Y1 - 10.9 ohms
RW to Y2 - infinite resistance
RW to Y3 - Infinite resistance
Y1 to Green - infinite resistance
Y2 to Green- 5.0 ohms
Y3 to Green - infinite resistance
Appears that the rectifier needs replacing since most of the values are out of spec.

Checked the Regulator next
Black To White - 10.2 ohms (spec is 0.5 - 30)
Black to Green - 1.8 ohms (spec is 0.5 - 20)
White to Black 6.48 ohms ( spec is 1.0 - 30)
White to Green - 6.5 ohms (spec is 0.5 -30)
Green to Black - 1.8 ohms (spec is 0.5-20)
Green to White - 10.34 (spec is 1.0 - 50)
Regulator portion is OK.

So based on the above checks, I'm thinking

1) that the RR needs to be replaced since I'm getting infinite resistance on the yellow wires and spec is 0.5-50 ohms)

2) Assuming I checked stator correctly (with engine running) my readings are above spec, 12.3,12.48,12.4 (spec is 8-10 V). Does this equate to stator replacement). Would both fail at the same time, (unlikely I think)
As always thanks for any input.

[Rick Pope]

Take a good look inside all the connections. Corrosion inside the plugs is a real issue. Don't ask how I learned this.......

Poor connections, especially in the red connector, leads to heat because of increased resistance. This leads to r/r failure and ultimately a fried alternator.

[NobleHops]

Tony, I’m not sure that you can test a R/R without a load. They have sensing and delay circuitry designed to smooth out their output. All of your other components seem to be testing fine.

I’d look at the simplest stuff first as Rick suggests. One of the biggest culprits is the alternator connector, and the small red connector that feeds back to the battery. It is typical to find those over heated and the wire brown and corroded, which creates a ton of resistance. We replace that short pigtail to the solenoid with new uprated wire, spades, and ATC fuses.

The next best step is to measure voltage drop on the path of current through the ignition and the key switch. The keyswitch base is notorious for getting gummed up and introducing a lot of resistance, and so is the rotary kill switch.

[oldbikerdude]

Thanks for the input, guys.
Every connector on the bike including the RR and alternator connectors are in very good condition. No browning of wires and no corrosion.
Also put dielectric grease on all connectors when bike was refurbed this past winter. At the time I also disassembled the key switch base and all contacts were cleaned.
The only item I didn't refurb mentioned above is the rotary kill switch, which is now on the to do list.

I went through the electrical checks again, and here is what I found. I'll try to break it down so it makes sense.
1) Stator checks,
checked stator wire harness, I have consistent 7.8 - 7.9 V on the 3 yellow wires to ground with bike running.
checked stator windings, bike not running, 6P connector disconnected, all read 0.4-0.5 ohms as before.
checked continuity to ground, each yellow wire to ground, all read 0L as in no resistance, so coil wires are not grounded to the case.
checked stator black to white wires, measures 11.1 V (spec is 10-12 V)

2 Rectifier checks,
1) Battery
I trickle charged the battery to full charge, this is a brand new battery when I got the bike 1 year ago.
Battery not running - 13.0 V
Battery ignition on - 12.5 V
Battery at 1000 rpm - 13.9 V
Battery at 3000 rpm - 14.7 V
Wanted to see if there was a voltage ceiling, looks like I hit it.

2) Checked input signals to regulator, they were checked on wire harness side (not RR side), 6P disconnected.
measured 0.00 ohms, so tells me no wires loose or corroded frame grounds.

3) Checked DC voltage of R/W wire to Ground, should be battery voltage.
Voltage reads 13.18 V, same as battery at rest.

4) Checked for breaks in coil, ignition on, reading DCV, +ve multimeter (MM) lead to to Black wire and -ve MM lead to Ground.
Measures 12.35, battery voltage, so no breaks in coil or excess resistance.

5) Went through the rectifier checks as shown in Honda Service Manual page 16-12.
R/W wire (+ve MM lead) to Green wire (-ve MM lead) - 17.1 M ohms or 17100 k ohms, (spec is 0.5-50 k ohms), so higher than spec
R/W wire to Y1 - 7.9 M ohms (or 7900 k ohms), also higher than spec (spec is 0.5-50 k ohms)
R/W wire to Y2 - 0L, open circuit, no resistance, should be seeing some resistance
R/W wire to Y3 - 14 M ohms ( 14000 k ohms), higher than spec (spec is 0.5-50 k ohms)

Checked each Yellow wire ( +ve MM lead) with Green wire (-ve MM lead)
Y1 to Green - 0L or open circuit, no resistance, (spec is 0.5 -50 k ohms), so out of spec.
Y2 to Green - 5.56 M ohms or 5560 k ohms, ( spec is 1.5 - 50 k ohms), higher than spec
Y3 to Green - 0L or open circuit, out of spec.

3) Regulator checks (diodes), Honda Service Manual page 16-12
Black ( +ve MM lead) to White ( -ve MM lead) - 10.16 M ohms or 10610 k ohms, higher than spec (spec is 0.5-30 k ohms)
Black to Green - 1.8 k ohms, (spec is 0.5-20 k ohms), this diode is in spec.
White to Black - 6.47 M ohms or 6470 k ohms, higher than spec ( spec is 1-30 K ohms)
White to Green - 6.5 M ohms or 6500 k ohms, higher than spec ( spec is 0.5-30 k ohms)
Green to Black - 1.8 k ohms, within spec, (spec is 0.5 - 20 k ohms)
Green to White - 10.3 M ohms or 10300 k ohms, higher than spec ( spec is 1-50 k ohms)

Sorry for all the data here, surely not easy to go through.
The error with my original post is that I didn't notice that my multimeter screen was showing M ohms and the spec in Service Manual
was calling for k ohms.
Note that 0.5 k ohms ( lower spec limit) is .0005 M ohms
and 50 k ohms ( upper spec limit) is 0.05 M ohms.
Many of the values above are over the spec limit, with a few open circuits that should show some resistance.

So with the above info, I'm pretty sure that my stator and coil are good, but my RR is kaput.

Has anybody out there replaced their RR recently.
Anyone have a preference as to manufacturer, saw that Ricks Motorsports and Electrosport and Electrex offer RR's.
Apparently Electrex is Mosfet technology, from the UK, the others are not Mosfet and available in the US and Can.

Input is still welcomed.

[oldbikerdude]

By the way, Nils, I did look for some info regarding RR testing without load but couldn't find any.
I did see some info on testing RR's without load being applied. The service manual also states to disconnect the RR connectors when testing.
Can you expand on your statement.

[daves79x]

I re-read your posts and can find no where that you checked the resistance between the slip rings on the rotor. Should be around 4 ohms, give or take. That is a very common problem and the first thing you should check (after brushes) when looking for a problem.

The simple stator test is that the 3 yellow wires should all show continuity with other but no continuity to ground. RR tests are usually meaningless. Only to know for sure is to plug in a known good unit.

Dave

[oldbikerdude]

Thanks Dave, will check the resistance on the slip rings and rotor as well as the brushes.
I have put about 4000 kms on since refurb, and checked brush length and resistance between slip rings at that time, I may have recorded it in my service manual. Will check when I hit the garage. This will be a good check to see brush length changes over the 4k kms.
I still don't understand why the RR tests are meaningless, the manual states to check RR with plugs disconnected.

[oldbikerdude]

Just checked the brushes and the length still has lots of meat left.

IMG_7394.jpg

I also measured the resistance from one slip ring to the other and got 4 ohms, (spec is 3.5 - 4.8 ohms)
Did record the slip rings resistance on Jan 4/21 and measured at 4.1 ohms.
The alternator clutch plates are still both in great shape.
The depth of the slip ring grooves are 0.4mm (.015")
Can I clean up this surface to remove the grooves?
Thought I saw a post in the past where someone cleaned this surface up.

IMG_7392.jpg

[daves79x]

Some of these groove like that, tends to be the late models, don't know why, but has obviously to do with copper hardness and brush hardness. They don't hurt anything, you can certainly clean the rings up with Scotchbrite, but don't try to remove the grooves. Your ohm reading is fine. I suspect the RR in this case. I'm lucky in that I have several spares to try, but you'll have to spring for a new one unless you know someone that will loan you one to try.

Dave

[oldbikerdude]

My CBX is definitely late model, 9/81 build date. Just cleaned up the grooves and reassembled.
Re the RR, wish I did have a spare one to try out, but no luck with that, so I ordered a new one.
Will update thread once I get the new one.
Thanks for the help.

[Archstanton]

Gents. Forgive me if i have missed this anywhere else I have looked around but unable to find my answer.

My 1978 Rotor has failed, reading 1.4 ohms, I need to send it away to get it rewound, could someone advise me as to how i remove the shaft from the rotor , Eg, which side the rotor slides off of the shaft etc and any other tips you may have for doing this.

Thanks in advance

Arch

[daves79x]

You have to press the shaft out of the rotor. The side with the larger diameter is the big end of the taper.

Dave

[NobleHops]

Stated differently, press on the end without the threads, after removing the nut and washer.

[Archstanton]

Perfect Many Thanks Gents!

Cheers Arch