Topic: would an extra ground wire do any good on the.....................

[bucky katt]

.........coils from the frames of the coils to a good physical ground? with the frame painted i dont know how well, if at all the coils are grounding to the frame.

[kslrr]

The coils are not grounded via their frames.  The "ground" path is the wire to the points.  The only reason the coil frame mounts to the bike frame is rigidity.

[paulages]

people often confuse the "ground" pat as meaning that the electricity actually goes to the ground via the frame. think of it as a return path instead... in order for the electrons to flow and do work for you, they need to get from one side of the battery to the other. in our bikes we use a negative ground, and the green wires are the direct path to this terminal. there should be a big green wire in your harness, meant to attach at the coil mounts. this is your ground path.

before electricity was as well understood as it is now, vehicles would in fact use the frame as a ground path, but this is inconsistent and caused much of the charging problems in older vehicles. think of the frame as a backup plan on yours. except for the spark plugs, i believe every system in our bikes use the direct green path... the main ground strap from the battery to the frame does attach at an engine mount, but i usually add a wire from the head to a green junction.

[bucky katt]

thanks for the info and insights gents...........i do usually add an extra ground path from a green wire up front someplace, too many grounding points never hurt anything but too few sure can 

[Don R]

I agree with Bucky Katt, I have noticed the newer 750's around here have an added green wire at the coil area where my 70 does not. I may add a new green from the headlight bucket to the battery also, I seem to have a dim headlight. I probably need a relay.

[TwoTired]

.........coils from the frames of the coils to a good physical ground? with the frame painted i dont know how well, if at all the coils are grounding to the frame.

Coils don't need a frame ground operate, except where the points connect to the engine, then the frame, and then battery NEG.

Of course, any other electrical equipment on the bike needs to connect to the frame or the battery neg terminal somehow.

The frame is just an electrical conductor, used as a path for the current to reach the battery.  It is possible to wire a bike and never use a frame ground at all.

[HondaMan]

I agree with Bucky Katt, I have noticed the newer 750's around here have an added green wire at the coil area where my 70 does not. I may add a new green from the headlight bucket to the battery also, I seem to have a dim headlight. I probably need a relay.

Don:
The "extra" green ground junction on the later bikes was actually the original one under the seat: it got moved to the coils' location starting with the "F" bikes. It was very likely faster for the production techs to mount it there while mounting the coils, instead of going to another part of the bike and mounting it, typically under the seat latch. It also makes more electrical sense, since the coils are one of the highest current draws on the bike.

Generally, on the aging bikes we have, running an extra GREEN wire from the headlight bucket to the Voltage Regulator's connector will boost the electrical performance on these bikes. I've added many of these, and some BLACK backbone wires, too, from the headlight to the Voltage Regulator, as a convenient method of helping out the aging splices inside the harnesses. It usually raises the battery voltage a little, brightens the headlight, and improves starting. You can simply clip the new wire (20 AWG size is fine) into the existing ones with a 3M blue splice, or make a wye with the proper connectors at each end for a more professional approach. 

[mystic_1]

with a 3M blue splice

OMG you use those?  Say it ain't so!!!       

I hate them, for so many reasons, but they work, are easy to use, and are cheap so a lot of people use them.  Personally I solder any splices and heat-shrink or tape as necessary, or I make up y-adapters using bits from my big box of junk wiring harnesses

mystic_1

[paulages]

I agree with Bucky Katt, I have noticed the newer 750's around here have an added green wire at the coil area where my 70 does not. I may add a new green from the headlight bucket to the battery also, I seem to have a dim headlight. I probably need a relay.

this is to connect the green circuit to the frame.

[HondaMan]

with a 3M blue splice

OMG you use those?  Say it ain't so!!!       

I hate them, for so many reasons, but they work, are easy to use, and are cheap so a lot of people use them.  Personally I solder any splices and heat-shrink or tape as necessary, or I make up y-adapters using bits from my big box of junk wiring harnesses

mystic_1

Personally, I don't use them, but for the novice they often make a better connection than the K-Mart crimpers and solderless connectors will. 

[mystic_1]

with a 3M blue splice

OMG you use those?  Say it ain't so!!!       

I hate them, for so many reasons, but they work, are easy to use, and are cheap so a lot of people use them.  Personally I solder any splices and heat-shrink or tape as necessary, or I make up y-adapters using bits from my big box of junk wiring harnesses

mystic_1

Personally, I don't use them, but for the novice they often make a better connection than the K-Mart crimpers and solderless connectors will. 

Aye to that   Although the local K-Marts around here have all closed down so the cheap tool alternative is Walmart or Harbor Freight




Back on topic, adding extra ground wires certainly isn't going to hurt anything but shouldn't be used as a band-aid.  The stock configuration should work.  If you have a problem inside your harness, then the odds are good that the ground isn't the only problem and you should be doing some surgery on the harness.  It seems daunting I know but with care it only takes a couple of sessions to strip and rebuild the harness.  A couple of hours to get it out, a few hours working on it, a couple hours getting it back in.  It's all color coded and keyed so it's pretty straight forward, just there's LOTS of connections especially in the shell.  Fixing any problems you may find usually comes down to replacing wiring or re-soldering connections, little cost involved just time.

While the harness is apart, you could even upgrade the main ground runs to larger gauge wire (or run parallel redundant grounds), upgrade the main power runs similarly, add extra power lines for accessories or lights, etc.  Clean the connectors.  Re-wrap with self fusing tape.

With planning you'll only need to do this once, and you'll have a trouble-free harness for years to come.

mystic_1


PS do the next owner a favor and document your changes

[HondaMan]

with a 3M blue splice

OMG you use those?  Say it ain't so!!!       

I hate them, for so many reasons, but they work, are easy to use, and are cheap so a lot of people use them.  Personally I solder any splices and heat-shrink or tape as necessary, or I make up y-adapters using bits from my big box of junk wiring harnesses

mystic_1

Personally, I don't use them, but for the novice they often make a better connection than the K-Mart crimpers and solderless connectors will. 

Aye to that   Although the local K-Marts around here have all closed down so the cheap tool alternative is Walmart or Harbor Freight




Back on topic, adding extra ground wires certainly isn't going to hurt anything but shouldn't be used as a band-aid.  The stock configuration should work.  If you have a problem inside your harness, then the odds are good that the ground isn't the only problem and you should be doing some surgery on the harness.  It seems daunting I know but with care it only takes a couple of sessions to strip and rebuild the harness.  A couple of hours to get it out, a few hours working on it, a couple hours getting it back in.  It's all color coded and keyed so it's pretty straight forward, just there's LOTS of connections especially in the shell.  Fixing any problems you may find usually comes down to replacing wiring or re-soldering connections, little cost involved just time.

While the harness is apart, you could even upgrade the main ground runs to larger gauge wire (or run parallel redundant grounds), upgrade the main power runs similarly, add extra power lines for accessories or lights, etc.  Clean the connectors.  Re-wrap with self fusing tape.

With planning you'll only need to do this once, and you'll have a trouble-free harness for years to come.

mystic_1


PS do the next owner a favor and document your changes

I think you're completely right! This rebuild task is made much easier with Del's parts at www.vintageconnections.com. He even supplies whole "rebuild kits" with the right connectors and some superior tubing (the black sheathing on the whole thing) that won't get stiff and crack after years. It' good stuff, and not expensive. I've rebuilt 2 harnesses now with his stuff, and it's first class. I think it was less than $20 per kit, so last time I bought several and got a discount.