Regulator/Rectifier replacement

[earlfor]

13.1 volts is a low a charge rate for 5k rpm. It should be 14.7-14.8.
I would disconnect the stator from the R/R and run the bike at 5k rpm and check the stator AC output voltage between the phases. It should be 80 volts AC at 5k rpm. (yes, you run the bike with the R/R disconnected):-)
If Ac output is at or near 80 volts, then either your new R/R is faulty, your battery ground wire is not making a good connection or there is a lot of wiring harness resistance.

The guy at CRC2 said he thought it questionable to connect R/R 12v negative directly to battery because the battery may have a poor ground.
that doesnt make any sense to me since if the battery has a poor ground, connecting R/R negative to the ground wire is not going to result in a better ground. However, connecting the R/R directly to the battery negative terminal is a more direct/efficient path.

Earl

Welp...it's alive again. Battery reads 12.75 hooked up to the bike. At idle (1500-2000) it charges at roughly 13.4 volts and at 4500-5000 RPM it charges at 13.10 volts.

This is with the 'San Franscisco' wiring, W/green and W/pink tied together (eliminating the headlight switch). It's an improvement...

Not sure where I want to go next, but I'm going to sync the carbs.

~Adam

[dpep]

The guy at CRC2 said he thought it questionable to connect R/R 12v negative directly to battery because the battery may have a poor ground.
that doesnt make any sense to me .............

I thought this a strange statement also. How can the battery have a bad ground? The battery IS the ground. A bad ground means there is a break in the path back to the negative terminal of the battery. If the battery has a "poor ground" you've got a bad battery. Have I missed something here?

[AOD]

What if the plates on the battery start to short and die out? *shrug*

I'm curious how 13.1-13.4 volts will work at charging the system...but I'm worried about the heat on the new R/R. Earl or Sandy, how warm does your R/R get to the touch?

~Adam

[Sandy]

I can't tell you how warm it gets because I've never actually checked, but I don't think it should get to the point of being uncomfortable to touch. As for the voltage you're charging at, it's too low and the extra voltage you should have for some reason is being turned into heat by the sound of it. You mentioned you checked this before you mounted it, mount it then check it as this will give you a better ground to the frame as well as allowing for a better heat sink. A fully charged battery will actually be around 13.4 volts. If you're not charging significantly over that (14.8 or so) you're going to have problems. As for the shorted battery cells, if you measure the battery voltage on a charged battery it should be around 13.4 volts if you have a shorted cell it will measure around 11 volts after a short while after charging, subtract 13.4/6 for each dead cell. Gotta go but I'll be checking my email more in the next day or so.

[earlfor]

For your electrical system, consider that devices/accessories that consume power (draw) are one side of the system. Devices that charge the battery are a different side of the system. I am wondering.............I suggested that in your R/R installation (the charging side) you wire the R/R directly to battery. This is the most efficient way of connecting it. As I understand it, you have wired it to "San Francisco" through the draw side of the system.
I think it probable there is a excess resistance and consequently an over draw problem on the device side. My opinion is that as a consequence, the problem is now extended to the charging side of the system also due to the roundabout wiring. Before trying to troubleshoot the low electrical level, I suggest isolating the two halves of the system by wiring the R/R in the most efficient manner.

The R/R on none of my bikes gets more than a couple degrees warmer than my hand. That would be about 100F.

13.4 volts is not going to charge the battery to much more than about a 10% charge level. Or, to be more professional and technical,............it aint worth a schitt. :-)

Earl

What if the plates on the battery start to short and die out? *shrug*

I'm curious how 13.1-13.4 volts will work at charging the system...but I'm worried about the heat on the new R/R. Earl or Sandy, how warm does your R/R get to the touch?

~Adam

[Anonymous]

HI ALL.
just thought I'd put my 2 cents worth in here.......... I replaced my original R/R ( 1980 850G ) just yesterday, an earlier post suggested to connect the + wire to the battery ( or solenoid ).
The instructions with my new unit kind of stressed to connect to a wire which is live only with the ignition switched on.. they used the rear brake light feed as an example. I found an inline multi-plug coming from the fuse box with such a wire in it... slipped the fitting from the multi-plug and soldered to the side of that fitting. My only reasoning for this is a faint chance of current flow may be drawn from the battery if you source from it directly...I realy don't know but I did as directed.

The new unit has a slightly wider spread between the mounting holes, so I decided to mount it in a different place, I was also concerned about the lack of cooling airflow under the battery box ( the position for the original R/R ) so I welded a suitable length of 1" flat bar to the frame, in a vertical attitude, imediately behind the LEFT side cover spanning the ' D' shaped area which supports the rear foot-peg.
I placed the flat bar slightly inside from centre of the aformentioned framework ( to allow fitting of the supplied wiring multi-plug ) then bolted the R/R to the inside of the flat bar. So what you see now is the flat bar then the back of the R/R, with the wiring multi plug toward the front. This position gives me plenty of airflow and was probably quicker than stuffing around with the base of the battery box. With a squirt of handy primer and gloss black, she looks OK to me.
I know it's not going to be original looking but, it works and dosn't look bad at all.

Well that's my 2 cents (plus a bit).

'til next time

stay upright

PS
I must echo an earlier post..... the knowledge base which comes from you all, and your willingness to help and support others, like me, is nothing short of amazing..... and I for one , thank you all sincerely.

[argonsagas]

If your reading of the instructions is accurate, then the instructions are either wrong or, at best, misleading.

Red/positive/+ wire must invariably be connected to the battery plus side terminal, whether directly or to the next main electrical hub. On a GS that would be the solenoid hot/plus terminal, which has the heaviest gauge wire leading up to the battery, and thus, the lowest loss. This is to ensure the maximum current and voltage arrives at the battery.

The more smaller gauge wire, and the more connections, you run your main lead through, the greater will be the voltage loss, and system efficiency drops, especially at time of high demand, when all lights/igntion etc are ON. If you happen to choose too thin a gauge wire for the connection, there is also a chance of overheating the wire and/or its connections, and causing other problems.

If there is reason to consider a slight draw from some other source, one that persists when ignition is turned off, then it is time for some further consideration, this time to consider finding and eliminating that source, because it should not exist.

[AOD]

I reckon I'll try wiring the red + wire going from San Francisco to the battery directly to the battery and see what it does.

I'm still skeptical, as it looks like it may be stator related in the end.

~Adam

[earlfor]

I thought I already gave instructions for checking AC stator output.
Maybe I'm just losing my mind. LOL If you dont have the correct AC output to start with, then nothing that follows is going to be correct. You cant make lemonade if you dont start with water. :-)

Earl

I reckon I'll try wiring the red + wire going from San Francisco to the battery directly to the battery and see what it does.

I'm still skeptical, as it looks like it may be stator related in the end.

~Adam

[AOD]

Yeah Earl, you did tell me how to check the stator output. I need to do that I guess...I think I'm scared to becuase I know it's not going to be pretty...

~Adam

[earlfor]

The good news is that you have confirmend I have once again made it through another day without becoming insane. LOL

Check the stator output, we gotta get to the bottom of this little pecadillo.
NO, thats not a peckerdillo. :-) Charging systems are just not that complicated. It cant be this difficult. :-) :-) :-)

Earl

Yeah Earl, you did tell me how to check the stator output. I need to do that I guess...I think I'm scared to becuase I know it's not going to be pretty...

~Adam

[AOD]

I meant to ask...do I just ground to the battery when checking the output of the stator?

[earlfor]

Thats a BIG NO !!!! The battery is DC current. The stator is AC current.

There are three wires coming FROM your stator. Each wire represents a different AC phase. The potential between any two phases should be 80 volts AC when the engine is running at 5000 rpm. The check must be done at that engine rpm to be accurate because stator output varies with engine rpm. The three stator wires end in a plug. Disconnect that plug. This means for the test, the stator is not connected to anything what so ever.
Usually the three stator wires will be yellow, but color does not matter as they are all electrically the same, just in different phases. Set your multimeter to the AC scale, AC scale yes AC scale :-) :-) 200V setting.
If we number the three wires of your stator 1,2 and 3, then you want to put one of the meter probes on wire 1 and the other probe on wire 2 to check the first phase output. Next put one meter probe on wire 2 and the other simultaneously on wire 3 and check output on this phase. To check the 3rd phase place the meter probes on wire 1 and wire 3. It does not matter which meter probe (black or red) you use on a wire. There is no positive and negative in AC current.

Earl

I meant to ask...do I just ground to the battery when checking the output of the stator?

[AOD]

Thanks again Earl.

[earlfor]

I'm just happy you asked before connecting 240 volts AC to ground. LOL

Earl

Thanks again Earl.