Single Point Ground / SH775

**Doog_fresh** · 03-22-2023, 11:39 AM

Here is the second photo showing the RR side
RR bottom.pdf.jpg

1981 Suzuki GS650

**Rich82GS750TZ** · 03-22-2023, 12:59 PM

First, for unexplained reasons, when you type the # symbol followed by a numeral, the forum makes it a link to various, seemingly random places in the forum. Go back and edit your post and put a space between the # and the numerals 1,2,3 and 4 in your post. Then they'll display the way you intended.

Second. I'm no expert at this so bear that in mind. But I have been through all of this. Link in my signature to My Charging system sorted.

But here are my thoughts, anyway. And that's all they are. Not gospel, just the way I understand things.

# 1 - R/R neg could go to your battery neg. I have mine going to the SPG. Then one thick wire from SPG to ground. That's the point of the SPG as I understand it. Your various grounds from R/R, harness, and bolt through rear of engine case. (not sure if all GSs have this), then one wire from SPC to bat neg.

# 2 - R/R pos to battery pos w/ inline fuse. I have mine going to the harness where I believe it splits to bat pos and i tihink fuse block but don't recall exactly. Anyway it goes to exactly where the stock R/R red was wired to.

# 3 - Lets ignore the igniter, as it's not part of the charging system. I also believe the ground extra ground # 3 that you have attached to it is superfluous/not needed. (I could be wrong, but I've never seen anyone else find the need to attach an additional ground to this component).

# 4 - The R/R is grounded through the # 1 wire in your diagram. I believe that your # 4 wire is also superfluous/not needed. (I could be wrong, but I've never seen anyone else find the need to attach an additional ground to this component).

Extra Thought: You don't mention your wiring from the stator to the R//R. Part of the wiring cleanup and gaining back voltage loss from corrosion/resistance/heat is the elimination of the loop that one of the stator legs takes (in the factory wiring) up to the left handlebar light control switch before returning to connect to the R/R. It does nothing. It is recommended to cut out this loop and wire all 3 stator legs directly to the Gray side if the SH775.

I'll rely on the real gurus to correct anything I may have gotten wrong here.

We don't know what bike you have (not that it matters a whole lot for this situation) It;s a good idea to put that info in a signature. That way you'll never have to repeat it, and we won't have to ask.

**Doog_fresh** · 03-22-2023, 02:12 PM

Rich82GS750TZ Thank for the profile / error correction will keep it in mind!

To start, the three wires from the stator are already recut (spaded) and attached to the SH775 and the original White/Red wire for the headlight switch was cut out from the harness.
# 1-5 in response

1: So you have a R/R neg to SPG then thicker wire to another frame ground and then to Bat neg? That's how that your wording appears to me, do you mean you have all components attached to SPG then a thicker gauge wire ran from SPG to Bat neg?

2: The way I interpreted Ed's write up and another post, the Pos R/R with an inline fuse is to help tie it into the system without overloading the old fuse box and give direct power?

3: Yes, the ignitor has nothing to do with the charging but the grounding cable from it is original. I was wondering if it was apart of the return current or if it's just an extra grounding cable from factory.

4: the # 1 wire is direct bat -, and # 4 is R/R to frame ground (and or SPG)

what about the starter solenoid?

1981 Suzuki GS650

**Rich82GS750TZ** · 03-22-2023, 02:43 PM

1. I have all components attached to SPG then a thicker gauge wire ran from SPG to Bat neg. All B/W harness grounds, R/R ground wire (your # 1) wire, and the engine case bolt ground wire connect to the SPG, then one wire from SPG to bat neg. This is just how I did it. It's not the only answer.

2. You may be right. You'll have to ask Nessism about the reasoning.

3. I don't recall my igniter having a ground wire on it's mounting bolt. I'll take a look. My wiring diagram appears to indicate that the igniter is bolted to the battery box- there is a B/W ground wire in one of the igniter leads in the plastic connector.

4. I don't believe you need # 4. But I don't think it will hurt you.

The starter solenoid is typically grounded though it's backing plate bolted through it's mounting plate/bike frame, no separate ground wire.

Good job on the signature.

**salty_monk** · 03-22-2023, 03:15 PM

I think it's just so all the grounds follow the same path. It's pretty simple to do in practice

**Doog_fresh** · 03-22-2023, 03:40 PM

Let me re-mock everything back on the bike and maybe it'll start to make more sense (and photos).. After I get this pilot jet out of the carb or throw it into the ocean lol...

1981 GS650
- Doug

**Brendan W** · 03-22-2023, 06:12 PM

My 2c
The R/R is what runs the bike. It needs to know what the system voltage is. Roundabout return paths like using the frame has the potential to fool the R/R by losing a volt or two resulting in lower effective supply voltage to the system.
All earth/ground wires go directly to the R/R ground wire. Take the ground wires off the frame above the airbox and go direct to the R/R.
Make a collection point for all these wires. I used one of the starter relay mounting studs. In principle the SPG could be a 6mm screw hanging in mid air, as long as all the wires are attached.
The battery box is an unreliable ground. By using a starter relay stud as the SPG you are assured that the relay coil is grounded.
The battery is secondary in the SPG idea. Effectively it is run in parallel with the bike. A separate wire is run from the battery negative to the single point ground.

**Nessism** · 03-22-2023, 06:18 PM

I have no SPG wisdom to share. What I do know, though, is that the + output from the R/R should feed the red wire in the harness, which splits, with one leg feeding the bike, and the other the fusebox, on the way back to the battery.

**Doog_fresh** · 03-22-2023, 09:30 PM

Thanks for all your input, I struggle like most to understand the concept, I'll report back later with the next concoction.... after I replace Blogs carb, if anyone has one laying around, I'll happily buy it off you!!!!!!!!!!!

1981 GS650GL

**Brendan W** · 03-23-2023, 05:55 AM

We have talked the SPG concept to death here. Some notice no difference between it and the factory concept.
The R/R outputs about 14 Volts and with any luck that's what your lights, ignitor, coils etc will see.
However if there are voltage losses on the return wires such as frame connections and if the battery is in the loop then the R/R can have a false idea of what is going on.
The SPG gives the R/R the clearest possible view of the bike and can result in better voltages and better battery charging.
The fact that the charging system is marginal by modern standards makes the SPG idea more relevant.
Voltage losses can happen on the supply side as well. A good regime of connection cleaning will most likely head off most if not all of the supply voltage problems but not the battery charging issue.
Again the claimed benefits are marginal and get less as connections are cleaned and that's most likely why many of us don't see stellar improvements.
I just like the idea of the R/R running the bike like a small power plant and it having no distractions like frames and batteries in it's primary role.

**Doog_fresh** · 03-26-2023, 09:06 PM

Thanks for your help, the SPG and RR+ comments all just clicked and I can mentally see it now; time to wire it up, reloom and get it fired up.
heers!

81' GS650GL
-Doug

Single Point Ground / SH775

Single Point Ground / SH775

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