1982 GS650 G - battery ground question

[d_sal]

Hi Folks,

As I'm a newbie to not only the world of motorcycles, but the gs forums as well, a little introduction first. Let me premise this by saying that I'm not much of a wrencher, however, as I really want to get this bike up and running I'm eager to learn and go through the necessary process to get my bike in tip top shape.

I've got a 1982 GS650G with 9k miles on it. It's running, however the battery is not charging (surprise, surprise! I know, stator/RR test are in order). The bike has some rust on it, particularly the battery box. I've looked at the wiring diagram for my bike, and it shows two grounds coming from the negative battery terminal. On my bike, these are grounded to the battery box.

The terminals on these grounds, as well as the location of the grounds, are rusty and corroded (see photo) and clearly need to be replaced. As I'm trying to learn as much as possible, my question is the following: In theory, if these two grounds were completely cut out, how would it affect the performance of the electrical system / bike? I thought the main battery cable from the negative terminal to the crank case was the battery ground. As usual, any and all input is greatly appreciated.

Also, should I be looking for a specific gauge wire to replace these grounds with?

Thanks,
Daniel

[tom203]

Only 9k, must have been hiding somewhere waiting for 3 stooges to return! Anyways, there should be a big black wire running from battery negative to engine bolt- right below carbs- this is or was the main ground point. Also there was a liitle black/white wire attached at battery negative terminal that probably left factory attached to battery box- this little guy has caused lots of charging woes, cuz corrosion destroys its connection with frame ground making decent charging unlikely. There's a bunch of ways to improve on this, but basically you want this wire directly attached to R/R ground and igniter ground. You must still have the big black wire bolted to engine, right?

[Nessism]

Great job figuring out how poor the Suzuki R/R grounds are. Take your R/R ground and extend it so it will reach a proper frame ground point or take it direct to the battery.

The stator feed wires have a likewise poor routing method; one leg of the stator runs up to the LH handlebar switch, then turns right back around and heads to the R/R. This out and back leg is for back when the headlamp switch was manual (one leg of the stator was cut out when the head lamp was turned off), but now a days all the extra wiring adds resistance and heat, and often the harness melts down along this wire. I strongly advise you to rewire the charging system to feed the stator wires directly into your R/R, bypassing the factory harness. Needless to say, check the AC voltage on these stator wires before you do anything else though since that will help judge the condition of your stator.

Search out the Stator Papers and follow the flow diagrams on what to do.

Good luck and hope you get it sorted

[Steve]

The terminals on these grounds, as well as the location of the grounds, are rusty and corroded (see photo)

Sorry, but even clicking on the photo did not bring up anything large enough to see.

In theory, if these two grounds were completely cut out, how would it affect the performance of the electrical system / bike?

Simply removing them would have a GREAT impact, the bike won't work.

If you remove and replace them, it might help, but you reed to use a meter to see if your connections are bad now. If they are not bad, replacement won't help.

I thought the main battery cable from the negative terminal to the crank case was the battery ground.

That would be the ground wire for the cranckase, to make sure the starter motor has a good return path.

There should be another wire to the chassis. It might be from battery to chassis, it might be from engine to chassis.

There will likely be a third wire from the plate near the battery box that grounds the starter solenoid and R/R.

As much as practical, all these grounds should end up at one point with no loops.

Also, should I be looking for a specific gauge wire to replace these grounds with?

The size of the wire will depend on the expected current. The starter wire (feed and ground) will need to be about 8 gauge. Other main feed wires might be 12 or 14 gauge, depending on what they are feeding. Ground wires will be carrying the same amount of current, and it adds up. If you gather all your grounds together, then run that to the battery, that last run to the battery will be carrying all the current, so should be 10 or 12 gauge.

.

[d_sal]

AH! I Cannot seem to get an appropriately sized image uploaded. Hopefully I can sort this photo stuff out soon. What I do know however, is that before I start any electrical testing, I should take care of these corroded wires.

Thank you for your input. I'll be sure to post a follow up once I have at the electrical system.

-Daniel

[Redman]

....
....

Welcome to GSR.

First: The heavy black wire on battery negitive;
The heavy negitive cable on battery negitive to back of engine is the ground for the engine, most notably the starter motor (biggest amp draw on entire bike, by far) and the spark plugs (plugs themselves). That connection on back of engine often gets over looked.
I do not think you need to replace the cable, just clean up the connections. Although do look at if there might be corrosion between the wire copper itself and the connector, in which case you might want a replacement connector. THis heavy wire to the engine is to handle all the current of the starter motor so all that current does not have to go thru, say, the engine mounting bolts to the frame.

Second: The black/white wire on battery negitive.
THis runs all through the wiring harness and has several other black/white wires spliced onto it at various places. THis/these are what provide the ground to all the other devices all over the bike. All the black/white wires are all connected together in the wiring harness.
And one of them should be connected to the bike frame, on some bikes it is under the seat up behind the battery box. This one is subject to corrosion also.
And another one is connected to the battery box. On some bikes it is connected right where the starter solenoid is mounted to the battery box, this is to ground the battery box because the battery box may not otherwize be well connected to the frame. Hey, you know, I had a 82 GS650G: I recall the black/white wire was connected on the bottom inside of battery box and one time it got broke off when installing a new battery and I was dead on the side of the road about 2 days later.

Now that you know the 1st and the 2nd thing (stop, do not proceed until you do understand it), if.... if ..... if that heavy cable to back of engine is not making good contact, then some of that starter motor current may go thru engine mounting bolts in an attempt to get back to battery and maybe a lot of current may try to flow through some of the little black/white wires to get back to the battery and some of those black/white wires turn into toaster heating elements, and burns some of them apart, and then you have about no ground wires.

And a 3rd thing: Do need a good ground wire on the battery box for multiple reasons
A) to provide ground for the regulator/rectifyer (or it can not charge, or may charge at too low a voltage)
B) to provide ground for starter solenoid.
C) if R/R fails it might dump lots of current down the ground wire and burn up your ground wire.
All of which is why folks recommend adding your own ground wire from the battery box to the battery negitive, so not relying on that black/white wire in the wiring harness.

.

[d_sal]

Just for reference, here is the photo I was trying to upload earlier. It's amazing how many things are answered on BassCliff's website. The ground wires are noted in the photo and both ground to the lower left side of the battery box.

[Redman]

......
..... The ground wires are noted in the photo and both ground to the lower left side of the battery box.

Can see the wire on the left is definatly black/white, and definatly connects to the thick battery negitive cable. So that is definatly a ground wire. And there should be some ground wire to the battery box, you say was to bottom of battery box. That is what I remeber on the 650G i had years ago.
As I said before, on 850 and 1100 have that wire on battery box at the same place the solenoid bolts to, and is same place for the R/R negitive wire.

THe wire on the right, seems to have a connector in line and can not specifically see if it has a white stripe. I am not so convinced it is a ground wire. Could be, but cant really tell from the photo.
Maybe clean up that wire a bit more to see better what color it is.

You have a schematic?

And if you wonder why we cant tell, or if we state some detail that is not specifically correct.... I have heard told that the 650s are the model that has some things different than all the other models. Lot of stuff is pretty much exactly the same (but bigger or smaller) on say 850s verse the 1000 or the 1100s, but 650s have some things different than all others.

.

[tom203]

The one attached to the big cable terminal is the stock setup- went to bottom of battery box (like Redman said); The other wire is likely an addon for something or maybe an attempt to correct the problem with another ground wire. While you have camera, take some more pics; take one of carbs from top view either side.

[posplayr]

Hi Folks,

As I'm a newbie to not only the world of motorcycles, but the gs forums as well, a little introduction first. Let me premise this by saying that I'm not much of a wrencher, however, as I really want to get this bike up and running I'm eager to learn and go through the necessary process to get my bike in tip top shape.

I've got a 1982 GS650G with 9k miles on it. It's running, however the battery is not charging (surprise, surprise! I know, stator/RR test are in order). The bike has some rust on it, particularly the battery box. I've looked at the wiring diagram for my bike, and it shows two grounds coming from the negative battery terminal. On my bike, these are grounded to the battery box.

The terminals on these grounds, as well as the location of the grounds, are rusty and corroded (see photo) and clearly need to be replaced. As I'm trying to learn as much as possible, my question is the following: In theory, if these two grounds were completely cut out, how would it affect the performance of the electrical system / bike? I thought the main battery cable from the negative terminal to the crank case was the battery ground. As usual, any and all input is greatly appreciated.

Also, should I be looking for a specific gauge wire to replace these grounds with?

Thanks,
Daniel

This post should answer most of your questions about grounding.

http://www.thegsresources.com/_forum/showpost.php?p=1615346&postcount=26

Additional reading on overall charging health.

Read about GS Charging Health

9K miles is pretty low mileage for an CA bike. Was it sitting for a long time? I'm in down town SB if you need a quick look.

[posplayr]

Welcome to GSR.

First: The heavy black wire on battery negitive;
The heavy negitive cable on battery negitive to back of engine is the ground for the engine, most notably the starter motor (biggest amp draw on entire bike, by far) and the spark plugs (plugs themselves). That connection on back of engine often gets over looked.
I do not think you need to replace the cable, just clean up the connections. Although do look at if there might be corrosion between the wire copper itself and the connector, in which case you might want a replacement connector. THis heavy wire to the engine is to handle all the current of the starter motor so all that current does not have to go thru, say, the engine mounting bolts to the frame.

Second: The black/white wire on battery negitive.
THis runs all through the wiring harness and has several other black/white wires spliced onto it at various places. THis/these are what provide the ground to all the other devices all over the bike. All the black/white wires are all connected together in the wiring harness.
And one of them should be connected to the bike frame, on some bikes it is under the seat up behind the battery box. This one is subject to corrosion also.
And another one is connected to the battery box. On some bikes it is connected right where the starter solenoid is mounted to the battery box, this is to ground the battery box because the battery box may not otherwize be well connected to the frame. Hey, you know, I had a 82 GS650G: I recall the black/white wire was connected on the bottom inside of battery box and one time it got broke off when installing a new battery and I was dead on the side of the road about 2 days later.

I agree, but it should be noted: (I looked at 7 bike schematics last weekend: GS1100EZ, GS1100ED,GS70EX,GS1000L,GS1000S,GS850GT,1980 GS850GT to confirm) that none of these bikes have any connection to the Battery (-) except the heavy lead to the engine case.

This means that for battery charging current to get back to the R/R(-) it has to go through the heavy lead (-) battery lead==> to the engine case ===> to the frame ==> to the frame mounted B/W ringlug at the battery box mount ==> through the harness B/W ====> to the other B/W ring lug (typically mounted at the solenoid mounting bolt) ===> and finally to the R/R(-) ring lug under yet another mounting bolt.

This is the biggest issue concerning proper charging!!!!

This makes the charging system very susceptible to the resistance in all of these contacts/connections/wires. By going directly from the Battery(-) to the R/R(-) the charging is greatly improved and you can expect less than 0.2V of voltage drop on the negative side.



So if that B/W connected to the Battery(-) is in good shape and it will reach, then run it to the R/R(-)

The other B/W wire with the in line conenction is another frame ground. It provides a path for frame engine currents to get back to the R/R(-) by going through the harness B/W.

This recommendation is related to both of the wires being mentioned by Redman. Suzki obviously made a mistake by allowing the charging current to have such a circuitous route to get between the battery(-) and the R/R(-).


Now that you know the 1st and the 2nd thing (stop, do not proceed until you do understand it), if.... if ..... if that heavy cable to back of engine is not making good contact, then some of that starter motor current may go thru engine mounting bolts in an attempt to get back to battery and maybe a lot of current may try to flow through some of the little black/white wires to get back to the battery and some of those black/white wires turn into toaster heating elements, and burns some of them apart, and then you have about no ground wires.

And a 3rd thing: Do need a good ground wire on the battery box for multiple reasons
A) to provide ground for the regulator/rectifyer (or it can not charge, or may charge at too low a voltage)
B) to provide ground for starter solenoid.
C) if R/R fails it might dump lots of current down the ground wire and burn up your ground wire.
All of which is why folks recommend adding your own ground wire from the battery box to the battery negitive, so not relying on that black/white wire in the wiring harness.

.

...................

[posplayr]

Can see the wire on the left is definatly black/white, and definatly connects to the thick battery negitive cable. So that is definatly a ground wire. And there should be some ground wire to the battery box, you say was to bottom of battery box. That is what I remeber on the 650G i had years ago.
As I said before, on 850 and 1100 have that wire on battery box at the same place the solenoid bolts to, and is same place for the R/R negitive wire.

If they will all streach to the same point that would make for a nice single point ground. Running one additional wire to the frame would provide the redundance frame ground to the other B/W ring lug.

THe wire on the right, seems to have a connector in line and can not specifically see if it has a white stripe. I am not so convinced it is a ground wire. Could be, but cant really tell from the photo.
Maybe clean up that wire a bit more to see better what color it is.

In any case it is best to not have that bullet connetor in the middle of a ground wire. With the redundant frame ground wire mentioned above, it would be fine to just conenct this wire to another frame ground as well and not worry about the intermediate conenction of this wire.

You have a schematic?

And if you wonder why we cant tell, or if we state some detail that is not specifically correct.... I have heard told that the 650s are the model that has some things different than all the other models. Lot of stuff is pretty much exactly the same (but bigger or smaller) on say 850s verse the 1000 or the 1100s, but 650s have some things different than all others.

.

.................

[Redman]

http://members.dslextreme.com/users/storagecliff/images/gs650_wiring_diagrams/1982GS650GZ-1983GS650GD.Jpg

Maybe not too much help for the specific details of the ground wires. Although it does seem to show a black ground wire with a connector at the R/R.

Schematic good for identifying wires based on color.

.

[tom203]

http://members.dslextreme.com/users/...983GS650GD.Jpg

Maybe not too much help for the specific details of the ground wires. Although it does seem to show a black ground wire with a connector at the R/R.

Schematic good for identifying wires based on color.

.

The original setup (on mine at least) had ground wire from R/R bolted to plate (under airbox) that also had igniter attached. Only additional ground wire from negative terminal was to bottom of battery box -the solenoid gets its ground from being bolted to battery box. Just extending this wire to igniter/reg plate boosted my voltage about .7 volts as I recall.

[d_sal]

9K miles is pretty low mileage for an CA bike. Was it sitting for a long time? I'm in down town SB if you need a quick look.

Yes, posplayr, I know for a fact that it has been sitting for the last 6-7yrs. However, I do not know the exact history of the bike before that. I'm actually in Goleta, for another year or so, while I finish up my graduate degree at UCSB. I'm currently working on replacing the petcock, and cleaning/syncing the carbs, but the next step is to address the electrical issues.