Starter Relay grounding?

[polletttim]

recently tore down my 81 gs650 that I purchased back in may - gutted/ cleaned carbs, cleaned inside gas tank, basically upgraded and fixed all ground wiring, fixed airbox issues, checked valve clearances, general cleaning/ inspection of overall bike, etc.

just got everything back together today - put a new battery and fresh gas in - turned key, clicked starter button - nothing, not even a "click" so right away thinking starter circuit issues.. jumped the relay starter and it started up right away. (runs decent btw)

many would say replace the starter relay right off the bat but I've read a few threads now where people are saying "make sure theres a good ground to the relay" the real question.. is there a reason why the battery box isn't grounded (are the rubber grommets between the frame and battery box for isolation from ground or just to dull vibration?) and would it be ok to go ahead and add ground under the starter relay mounting screw? - in doing so grounding the battery box.

side note: just before I started the bike I oiled the throttle cable, because it was sticking, and to do that I took apart the throttle assembly on the handlebars, which also includes the starter button and switch... so theres a strong chance the issue could be caused by me removing that assembly and maybe moving or breaking an already corroded wire or connection point BUT it was getting late and decided ill troubleshoot in the morning. but again is it ok to ground the battery box?

 

[Steve]

Yes. It's not just "OK", it is rather necessary to ground the battery box, mainly because of the starter solenoid.

If your fusebox has an Accessory fuse, there should also be two screw terminals at the end of the fusebox. One of those screws is the HOT from the fuse, the other one is a GROUND. Guess where it gets its ground? Yep, from the wire you are about to install.

Before you go taking things apart again, are you aware of the "safety" switch in the clutch? In Suzuki's infinite wisdom to protect us from ourselves, it was necessary to pull the clutch lever to be able to engage the electric starter. Many of us have bypassed that "safety" feature, but yours might still be connected, so pull the clutch lever and try starting the engine.

.

 

[tom203]

My 81 came with a wire from negative battery post with other end attached to battery box. This is a weak spot...for good charging purposes best to extend this wire to a better spot. I used one of the mounting bolts that hold the ignitor/regulator plate to the frame - this became my common grounding point . This helps the r/r "see" the battery better.

 

[chuck hahn]

You can make a wire up that will go behind one of the selinoid mount bolts and go right to the NEG post of the battery as well.

 

[polletttim]

perfect! so clearly the rubber grommets are just there to dampen vibration of the battery, not for isolation of the battery box. I'll get to it tomorrow and let everybody know how it goes.

one of the previous owners painted the frame and put grounds back on painted surfaces which burned up all of the grounds in the wiring harness, showing how important proper grounding is. I've added a "common ground" point on the frame, on a battery box mounting tab, right under where the starter relay is located, so I may just move that grounding point or add a 3 inch jumper lol:stupid:

Steve I'm aware of the safety switch from reading the wiring diagram in the maintenance manual, but I think ill leave that on there for now because I am one of those who need to be saved from themselves.

 

[Redman]

...........
just got everything back together today - put a new battery and fresh gas in - turned key, clicked starter button - nothing, not even a "click" ..............

Are yolu askng if the starter relay ground could be a suspect in the "nothing".....?
Generally the answer would be 'yes',
but in your case you said you "jumped the starter relay" and it started: If you meant you jumped the big terminals, then "yes" the starter relay ground could still be a suspect. If you menat you jumped the little terminal (for the startrer button circuit) and it started, then "No, the relay ground is no longer a suspect".


Other note: In the stock wiring there should be a blk/wht wire going to the starter relay mounting bolt. THis wire is TO GROUND the battery box (not to ground the wire).

 

[polletttim]

Redman my battery box isn't grounded at the moment and I jumped the big terminals on the starter relay to get the bike going. thanks for the concern haha I can see where people could get mixed up if they're not sure what they're doing.

when I removed all the factory grounds/wiring and replaced them I never noticed or maybe just forgot wether or not the battery box was grounded.. its all cleared up now and im gonna put a ground under the starter relay mounting bolt or something of the sort, which would ground the battery box.

 

[chuck hahn]

To test the slinoid, unplug the wire going to it. Use a jumper wire from the battery positive and touch the lead from the selinoid. If its good it will click. If it doesnt click add the ground wire and try it again. If it clicks it needed a better ground. If it still will not click its toast..replace.

 

[posplayr]

Redman my battery box isn't grounded at the moment and I jumped the big terminals on the starter relay to get the bike going. thanks for the concern haha I can see where people could get mixed up if they're not sure what they're doing.

when I removed all the factory grounds/wiring and replaced them I never noticed or maybe just forgot wether or not the battery box was grounded.. its all cleared up now and im gonna put a ground under the starter relay mounting bolt or something of the sort, which would ground the battery box.

I'm not going to explain all the theory, but if you simply implemented the SPG at your battery box, which I think mounts the ignitor, R/R, and solenoid you would be done.

If you dont want to do that, at least start replacing the word "grounded", with how is this current going to get back to it's source. The source can be either battery (when the bike is off) or R/r(-) (when the bike is on).

From your description, it is not clear how your harness B/W returns current to the R/R(-).

 

[polletttim]

I'm not going to explain all the theory, but if you simply implemented the SPG at your battery box, which I think mounts the ignitor, R/R, and solenoid you would be done.

If you dont want to do that, at least start replacing the word "grounded", with how is this current going to get back to it's source. The source can be either battery (when the bike is off) or R/r(-) (when the bike is on).

From your description, it is not clear how your harness B/W returns current to the R/R(-).

the ignitor and r/r are physically mounted under the airbox - not touching the frame at all and the starter solenoid is mounted on the side of the battery box.. if thats what you're referring to?

I'm not sure what previous owners have changed(if anything) but the wiring was a mess. I just tried to clean up the issues the bike had when I bought it - like 90% of the B/W in the main wiring harness were burned up (luckily not causing too much damage to surrounding wires in the harness) I replaced the burned up B/W with 14awg and brought it back to a point on the frame where the battery box mounts.. there I also have the r/r and a 14awg from the (-) battery post. so the r/r is fine

my main question was wether or not the battery box should be isolated from the frame (because of the rubber grommets), but thats cleared up now thanks to everyones replies - so I should be good to go in that sense.

I have decent understanding im just not good at explaining lol

 

[Redman]

.............. im gonna put a ground under the starter relay mounting bolt or something of the sort, which would ground the battery box.

Yes, you need to run a ground wire to there TO GROUND the battery box (and, more importanly; the starter relay and the R/R).

 

[posplayr]

the ignitor and r/r are physically mounted under the airbox - not touching the frame at all and the starter solenoid is mounted on the side of the battery box.. if thats what you're referring to?

I'm not sure what previous owners have changed(if anything) but the wiring was a mess. I just tried to clean up the issues the bike had when I bought it - like 90% of the B/W in the main wiring harness were burned up (luckily not causing too much damage to surrounding wires in the harness) I replaced the burned up B/W with 14awg and brought it back to a point on the frame where the battery box mounts.. there I also have the r/r and a 14awg from the (-) battery post. so the r/r is fine

my main question was wether or not the battery box should be isolated from the frame (because of the rubber grommets), but thats cleared up now thanks to everyones replies - so I should be good to go in that sense.

I have decent understanding im just not good at explaining lol

One reason why you are having a problem conveying what you are doing is the lack of a schematic representing the physical configuration.

Sounds like you made the frame the SPG with stacked connections for R/R(-), B/W harness, Battery (-) but left the battery box floating which causes the solenoid to have no return path. You have now added a ground for the battery. Running to the from battery box to same frame ground would be best given that configuration(although not critical). No reason to construct another B/W from the harness.

BTW I ran into the same burned ground wire problem back in 2007 when I first purchased by old GS750EX. To the best of my knowledge that ground wire burns because a poor ground on the R/R which forces all of the return currents through the harness (I actually had two B/W wires burned). This occurs because of overcharging beyond what old-style shunt R/Rs can control using single leg SCR control.

Fixing the ground as you appear to have done was enough to solve my bikes problem I never went to a Series R/R.


If you run the Stator Pages Phase A tests you can measure your changing system voltage drops and see how successful you really were in fixing the grounding. You will also measure the positive side which will probably be worse.

 

[posplayr]

Yes, you need to run a ground wire to there TO GROUND the battery box (and, more importanly; the starter relay and the R/R).

+2 ......................

 

[polletttim]

One reason why you are having a problem conveying what you are doing is the lack of a schematic representing the physical configuration.

Sounds like you made the frame the SPG with stacked connections for R/R(-), B/W harness, Battery (-) but left the battery box floating which causes the solenoid to have no return path. You have now added a ground for the battery. Running to the from battery box to same frame ground would be best given that configuration(although not critical). No reason to construct another B/W from the harness.

BTW I ran into the same burned ground wire problem back in 2007 when I first purchased by old GS750EX. To the best of my knowledge that ground wire burns because a poor ground on the R/R which forces all of the return currents through the harness (I actually had two B/W wires burned). This occurs because of overcharging beyond what old-style shunt R/Rs can control using single leg SCR control.

Fixing the ground as you appear to have done was enough to solve my bikes problem I never went to a Series R/R.


If you run the Stator Pages Phase A tests you can measure your changing system voltage drops and see how successful you really were in fixing the grounding. You will also measure the positive side which will probably be worse.

good info! when I start up the bike tomorrow (assuming the starter solenoid will work) I will do the stator pages phase A tests like you are suggesting.

 

[polletttim]

just put a short jumper from my SPG to under the starter solenoid mounting bolt and it starts properly with the push start button now.:stupid:

gonna head over the stator pages and check everything over. thanks for the input everybody!

 

[posplayr]

Here is a picture that might help you visualize how the current flows through your bike. The R/R(+) is the source of all power when riding. The battery is just a store that gets depleted if charging voltage does not exceed 12.8v (typ) which is the minimum required to push current into the battery.
The two green wires are usually not on a stock GS which is what contributes to the GS charging problems. The R/R and the battery are not tied together very well on the ground side increasing resistance and lowering charging voltage.

You can see current traveling in the frame, needs to crawl up one B/W ring lug wire to the B/W crimp in the harness then come out the other B/W ring lug to get to what is typically a solenoid ground. The R/R(-) ground wire is usually close to or stacked under the same mounting bolt.

By realizing all current coming out of R/R(+) the red wire, needs to return to its source on R/R(-), it is perhaps self-explanatory why that mounting bolt become the focal point for collecting up all currents so they can get back to the R/R(-). That final jump from SPG to R/R(-) has to support 14A and so care should be taken in making sure those connections are very clean and you are using a substantial(14 AWG) but short wire (<1 ft).

You should notice (if all connections are clean) that the only current flowing from the battery(-) to the SPG is the battery charging current (3 amps). Anything else like harness returns or anything through the frame (like Dyna-S) will get picked up by another path.

If you ground the R/R(-) to the battery (-) then all the 14 amps comes to that point before making what is usually a 2 ft wire to the R/R(-). It can work but it is far more likely to develop a larger voltage drop that way.

 

[polletttim]

Here is a picture that might help you visualize how the current flows through your bike. The R/R(+) is the source of all power when riding. The battery is just a store that gets depleted if charging voltage does not exceed 12.8v (typ) which is the minimum required to push current into the battery.
The two green wires are usually not on a stock GS which is what contributes to the GS charging problems. The R/R and the battery are not tied together very well on the ground side increasing resistance and lowering charging voltage.

If you ground the R/R(-) to the battery (-) then all the 14 amps comes to that point before making what is usually a 2 ft wire to the R/R(-). It can work but it is far more likely to develop a larger voltage drop that way.

perfect, easy to see. one thing about the stock R/R.. being shunt style.. is it constantly charging the battery or does it stop charging the battery every once in a while like a switch or shunt when the battery reaches a certain charge or the R/R gets to a certain temperature?

 

[posplayr]

perfect, easy to see. one thing about the stock R/R.. being shunt style.. is it constantly charging the battery or does it stop charging the battery every once in a while like a switch or shunt when the battery reaches a certain charge or the R/R gets to a certain temperature?

The stator is AC and pulsed but when you add all three together you pretty much get DC out. However, once the battery voltage gets high enough, the R/R will start shutting off during the advances of individual AC pulses. This tends to trim the voltage v.s. being completely shut off.

As far as the difference between SERIES and SHUNT, from the R/R DC output side they pretty much look the same. DC out with some ripple. It is what is going on with the stator where they are different. When the shunt "trims" the voltage, it does that by shorting out a stator winding. That clamps any voltage as it basically doesn't allow enough voltage for anything to come out basically disconnecting the R/R from the battery during the shorting process (due to blocking diodes in the bridge rectifier).

The SERIES is quite a bit different, there is no diode bridge, the SERIES can rapidly connect or disconnect from the battery to control voltage. When it disconnects the battery has to supply current and it is being depleted which stops charging. When the SERIES is connected, current can flow to the battery increasing voltage. Careful control of the timing allows output charging voltage to be maintained at about 14.5V.

The big deal in all this is that shorting the stator winding (by the SHUNT R/R) makes them run hot. So depending on how you ride your bike, how much oil it has in it, how much cooling capacity you are at the hairy edge of overheating the stator which eventually burns the insulation causing shorts.

If you ever pull your stator cover and it looks heat damage, you would be better off to get a Series R/R because this will relieve a lot of the stress on the stator and give many thousands of miles more lifetime to your changing system. This is because not only is the stator stressed by this shorting, the R/R is as well.

If you ever start changing out to LED's or have a burned out headlamp bulb, you are likely to way overstress the stator and R/R. That is because those old loads are no longer there and so the R/R has to short even more to control the voltage resulting in even more heat. It is even worse than that. The power that is dissipated in the stator can actually be much more than you might anticipate. That is because the power dissipated is proportional to stator resistance. You might only measure 0.5-1.0 ohms per leg at room temperature, at so there might be only 50-100 watts dissipated out of about 220 Watts max.

The problem is that when the stator heats up there is even more resistance but the same amount of current so the power can get much higher. You can even measure 50-75 degF(IIRC) the stator side cover temperature difference with a thermal imager.

 

[polletttim]

The stator is AC and pulsed but when you add all three together you pretty much get DC out. However, once the battery voltage gets high enough, the R/R will start shutting off during the advances of individual AC pulses. This tends to trim the voltage v.s. being completely shut off.

As far as the difference between SERIES and SHUNT, from the R/R DC output side they pretty much look the same. DC out with some ripple. It is what is going on with the stator where they are different. When the shunt "trims" the voltage, it does that by shorting out a stator winding. That clamps any voltage as it basically doesn't allow enough voltage for anything to come out basically disconnecting the R/R from the battery during the shorting process (due to blocking diodes in the bridge rectifier).

The SERIES is quite a bit different, there is no diode bridge, the SERIES can rapidly connect or disconnect from the battery to control voltage. When it disconnects the battery has to supply current and it is being depleted which stops charging. When the SERIES is connected, current can flow to the battery increasing voltage. Careful control of the timing allows output charging voltage to be maintained at about 14.5V.

Ok so you could see the voltage being "trimmed" while checking the battery voltage with the multimeter while the bike is running, correct? I noticed yesterday when I was doing the quick charging test that every so many minutes(give or take) it was as if charging would stop and it would maintain 12.8V then after another minute or so it would start charging again for a few minutes and give all the right numbers at 2500-5000rpm according to the quick charging test guide.. all within 0.2Vdc(+/-).. I was concerned there might be a loose connection or the R/R might have been on its way out.

The big deal in all this is that shorting the stator winding (by the SHUNT R/R) makes them run hot. So depending on how you ride your bike, how much oil it has in it, how much cooling capacity you are at the hairy edge of overheating the stator which eventually burns the insulation causing shorts.

If you ever pull your stator cover and it looks heat damage, you would be better off to get a Series R/R because this will relieve a lot of the stress on the stator and give many thousands of miles more lifetime to your changing system. This is because not only is the stator stressed by this shorting, the R/R is as well.

If you ever start changing out to LED's or have a burned out headlamp bulb, you are likely to way overstress the stator and R/R. That is because those old loads are no longer there and so the R/R has to short even more to control the voltage resulting in even more heat. It is even worse than that. The power that is dissipated in the stator can actually be much more than you might anticipate. That is because the power dissipated is proportional to stator resistance. You might only measure 0.5-1.0 ohms per leg at room temperature, at so there might be only 50-100 watts dissipated out of about 220 Watts max.

The problem is that when the stator heats up there is even more resistance but the same amount of current so the power can get much higher. You can even measure 50-75 degF(IIRC) the stator side cover temperature difference with a thermal imager.

I guess it all depends on certain variables like bike size, riding style, and climate. Where I live we only get a few weeks of summer weather where the temperature gets above 25?C.. most days are within the 20?C range(short riding season). It was a balmy 6?C yesterday when I did the quick charge test, which is unseasonably chilly. I would say my riding style isn't "aggressive" but more actively relaxed lol. Also I was reading how anything over a 750 is pushing the short life span of a stock R/R so my 650 is maybe just under that limit, again depending on certain variables. I don't know what the bike has been through with previous owners.
If I decide to mod the bike at all, in the near or distant future, ill probably try to get a series R/R so I can be confident about the charging system but right now im just getting the thing running good with stock settings so I can put a few kilometres on it this summer.

 

[posplayr]

Ok so you could see the voltage being "trimmed" while checking the battery voltage with the multimeter while the bike is running, correct? I noticed yesterday when I was doing the quick charging test that every so many minutes(give or take) it was as if charging would stop and it would maintain 12.8V then after another minute or so it would start charging again for a few minutes and give all the right numbers at 2500-5000rpm according to the quick charging test guide.. all within 0.2Vdc(+/-).. I was concerned there might be a loose connection or the R/R might have been on its way out.



I guess it all depends on certain variables like bike size, riding style, and climate. Where I live we only get a few weeks of summer weather where the temperature gets above 25?C.. most days are within the 20?C range(short riding season). It was a balmy 6?C yesterday when I did the quick charge test, which is unseasonably chilly. I would say my riding style isn't "aggressive" but more actively relaxed lol. Also I was reading how anything over a 750 is pushing the short life span of a stock R/R so my 650 is maybe just under that limit, again depending on certain variables. I don't know what the bike has been through with previous owners.
If I decide to mod the bike at all, in the near or distant future, ill probably try to get a series R/R so I can be confident about the charging system but right now im just getting the thing running good with stock settings so I can put a few kilometres on it this summer.

Trimming I'm referring to is happening during each electrical cycle of the AC waveform. That is 18 poles per revolution so it is happening many times per second. I doubt it is having any changes that are occurring over a minute or two.

The 750 engine surface area is about the same as the 1000 but 25% less combustion area. So you are in a better situation. Same for my 750E (16V) compared to a 1100E (16V). If you pull the stator cover and have a lot at what the stator looks like. Remeber that poor connections can cause problems.

I had a brand new electrosport R/R I was testing and comparing to FET and SERIES R/Rs. The electrosport immediately got very hot to the touch. It turned out the connector pins had not been crimped very well. This caused a slightly higher resistance that caused the R/R to think it was overcharging. The SHUNT R/R shorts the stator to counter what it through was over voltage (due to poor connection). It was probably frying the stator and itself till I pulled it out and cut the wires off and they it in the junk box.