PO's spaghetti-wiring of Mike's XS Rec/Reg

[Yamakazi]

I have: 1979 XS650SF, stock wiring (except for issue below).

I'm having charging/dead battery issues. In trying to figure it all out, I realized the PO had replaced the individual stock rectifier and regulator with what appears to be a Mike's XS combo rectifier/regulator (Part #24-2089). The replacement combo rec/reg has the same wires and matches with the photo at Mike's website. There are numbers on the back of mine but they tell me nothing (TRM 100384 2/09). I couldn't find any other seller selling a combo unit that looked like this one, so I'm guessing it's Mike's.

I'm just curious about the PO's method of wiring. I'm not sure the PO hooked it up correctly...at least it wasn't installed following the instructions that came from Mike's. My inclination is to re-do the hook-up following Mike's instructions:



My questions... Why did the PO hook it up this way, and can I re-do this without frying anything? The 2 "dead-ended" black and red wires (that used to connect to the old rectifier) had remnants of previous connections (black had some green, red had some red), as if the rec/reg may've been wired to them at one point. Do you think the PO installed it according to the instructions, but decided it didn't work...and then hooked it up their own way? Or, tried to hook it up right, but did it incorrectly and then found another way?

The current method seems to have the rec/reg red wire bypassing the fuse box, and maybe even the main switch.

Mike's rec/reg vs mine:



My current rec/reg set-up...
Wiring from the rec/reg:
- 3 yellow correctly wired to the original 3 white (but in a 3-space connector block instead of 6-space)
- orange correctly wired to (harness) green in a second 3-space connector.
- blue is connected to the red/white-stripe wire coming from the starter solenoid switch.
- red goes directly to the (+)battery terminal.
- green goes directly to the (-)battery terminal.

From the harness (original wiring):
- red and black wires (previously bundled with the white wires & connected to the old rectifier) now connect to NOTHING. They were taped and left as dead-ends.
- green (in the green/brown/black 3-space connector) wired correctly to orange
- brown (in the green/brown/black 3-space connector) connects to NOTHING on the opposing side of the connector.
- black (in the green/brown/black 3-space connector) connects to a black wire on the opposing side that runs down to and is bolted to the side of the battery box.

As I understand it, the battery box itself "floats" on rubber dampers and would not provide a proper ground??

I've added pictures to illustrate the current set-up:


Note: My generator brushes are fed by a black wire and a green wire (no brown down there).



Also...do I need to swap out 3 nylon screws for the 3 steel screws at the brush holder since the 70-79 rec/reg is configured differently than Mikes 80-84 (brown wire) version? I've seen the chart for the 80-84 version with a brown wire:



Whew! Any help would be greatly appreciated.

 

[littlebill31]

Holy Appalachian Iceburg Batman!! I would tear it all out first and then completely re-wire. Sounds like a pain, but that is a rats nest and will fail somewhere else. Second, you have to "de"ground the stator with nylon screws, as you mentioned, which yours is not.
And yes, the battery box has rubber mounts, therefore you need to run a lead from the negative terminal to the frame or another solid ground piece, not just to the box itself.

I looked again. Please re-wire that, seriously, for safety sake. That is pretty bad.

 

[XSLeo]

On Mike's is a direct replacement for the old reg and rec, the three nylon screws are not needed.
If the reg/rec was a replacement for the later, 80 up bikes, then you would need the three nylon screws for a 79 and older bike.
I do agree with littlebill on the rewire. Rewiring the bike isn't hard to do. It can be intimidating at first. The diagram you posted is a good one. It shows the basics with the early reg/rec and points. It shows the later TCI ignition and Combo reg/rec also.
Mike's has new connector kits. I might get them and wire the reg/rec in with them.
The diagram shows the power flow thru the regulators on both the early and late alternators.
On the early, power flows from the key switch on the brown wire to the reg. The reg uses this power to tell the battery voltage and to power the rotor. When you turn the switch on the voltage will be below the preset 14.5 volts. This low voltage tells the reg to send power to the brush on the green wire, at the brush power flows into the rotor, out the other brush where it gets grounded by the three metal screws and on a black wire back into the harness. The flow of power creates the magnetic feild that ecites the stator into creating AC voltage. This AC voltage goes out the three white wires to the rec where it gets converted to DC to charge the battery. As the battery charges the voltage rises. When it reaches the preset 14.5 volts the reg reads this on the brown wire and stops the flow of power to the brushes and rotor. This stops the magnetic feild, which stop the stator making AC volts. Battery stops charging. As the battery voltage drops below the preset the reg starts the cycle over again. It does the hundreds of times per second.
On the later combo reg/rec it works in a simular fashion. When you turn on the switch power flows out the brown wire to the reg/rec. The reg/rec uses this power to read battery voltage. Power also flows to one brush, thru the rotor and to the reg/rec on the green wire. At this point if the reg/rec reads voltage lower than the preset 14.5 volts it turns on the rotor by grounding the green wire. Battery voltage rises, at the preset voltage the reg/rec turns the rotor off. The combo reg/rec being solid state cycles thousands of times a second. With no mechanical parts it's much faster. This keeps the battery charged better.
You can see the early and late do the same thing, turn the rotor on/off. They just do it differently.
This is why when adding a late style combo reg/rec or the cheaper Chrysler reg you need to do the nylon screw mod. This ungrounds the one brush With out the nylon screws you are sending power out on the brown wire and straight to ground, this can blow fuses.
I hope this helps you understand your alternator a bit better.

 

[littlebill31]

Sorry, I was wrong. I forgot about the 2 types Mikesxs offers on the reg/rec. Yours looks like the correct one for 79, nylon screws not needed.

 

[Yamakazi]

Please re-wire that, seriously, for safety sake. That is pretty bad.

littlebill31...thank you. That's what i thought. It just did not look right...even before I started studying on it.

On the early, power flows from the key switch on the brown wire to the reg. The reg uses this power to tell the battery voltage and to power the rotor. When you turn the switch on the voltage will be below the preset 14.5 volts. This low voltage tells the reg to send power to the brush on the green wire, at the brush power flows into the rotor, out the other brush where it gets grounded by the three metal screws and on a black wire back into the harness. The flow of power creates the magnetic feild that ecites the stator into creating AC voltage. This AC voltage goes out the three white wires to the rec where it gets converted to DC to charge the battery. As the battery charges the voltage rises. When it reaches the preset 14.5 volts the reg reads this on the brown wire and stops the flow of power to the brushes and rotor. This stops the magnetic feild, which stop the stator making AC volts. Battery stops charging. As the battery voltage drops below the preset the reg starts the cycle over again. It does the hundreds of times per second.

XSLeo...that paragraph brought it all together for me. I'm actually able picture the flow now. Thank you.

It looks like I have some re-wiring to do.

These have been helpful diagrams:

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A little back story...

I purchased my 650 recently and had only ridden it a few times when it died on me while out one night. With some help from someone that saw me stranded on the side of the rode, we finally got it started and I rode it home (but only after keeping it revved high and running some stop lights/signs). Dim headlight/brake light, no turn signals/horn, dead battery. I knew I had an electrical issue, but didn't know what because I know jack about motorcycles. I parked it in the garage and decided to "learn" about it.

I've now spent hours at XS650.com combing thru comments, wiring diagrams and instructions from the experts here.

I've printed off wiring diagrams, traced lines with colored pens, high-lighted this and that to help me visualize and understand the electrical system. I propped up the seat and removed the generator cover, side covers, headlight & gas tank to get a better view of all the components and wiring. I bought a multi-meter from Harbor Freight and started experimenting with it...just learning how to use it. I knew I had electrical issues, but I wanted to familiarize myself with the system before I started trying to fix anything. I tried some testing but realized I'd better make sure everything was there and in the right place before I got too far into it.

(First thing I noticed, after taking the brushes out, was that one of the brushes was "stuck" in the plastic holder...it was not sliding up and down smoothly. It would bind about halfway thru the little square channel, as if the channel was too small. Luckily, I'd purchased some electric parts from Mike's before The Great Schism, so I had a new brush holder on hand. Yep, the "binding" brush now slides smoothly thru the new holder.)

Also, I've purchased a can of connection cleaner and some di-electric grease. I'll be checking connections for good contact.

Once I get everything in order, I'll get out my multi-meter, visit Curly's link for testing, and try to determine what is "good" or "bad".

http://xs650temp.proboards.com/index.cgi?board=Charging&action=display&thread=3461

I'll also be looking at making changes based on the suggestions at this website. I just want to get it operating the way it should be...

Thank goodness this site is here, and folks who are willing to share their knowledge!