Believe it or not!

[geniusloerts]

"I attached the end of the second (battery) ground wire to the ground wire in the tail light harness at the connector under the seat. Guess what? Light problem disappeared! Now, when depressing brake, with t/sigs or emerengency flashers on, the brakes lights are steady and bright. "

did you splice into the harness for that? I am doing mine as i type this and was curious.

[MPittma100]

Grounds

All grounds should be to the battery. A frame ground is a "short cut" at best. It is worth the effort to make this happen and will make life easier down the road.

MP

[crazy steve]

I don't know that I'd run all the grounds to the battery....

One problem you'll have is all batteries (even the so-called 'sealed' ones) will outgas around the terminal posts at least a little and cause corrosion. So your smaller harness ground wires can get damaged rather easily. And you do need a 'chassis' ground as at least a few bits need one to function, such as the starter and horn buttons and the front turns on the standards.

[geniusloerts]

On my special the taillights ground back into the wiring harness. I got my grounding harness made and all hooked up like mentioned by the OP. I did not do the taillight, but will get to it.

[MPittma100]

Covering a Lot of Ground(s)

By joining the factory chassis grounds together from the battery original (see pictures), you are essentially turning chassis grounds into battery grounds. By doing so = better lighting, starting, plug firing, etc. One other area to join is where several (factory) chassis grounds are ganged at a mounting screw for the regulator/rectifier (under the seat).

It is a good idea to use the star type washers at these grounding points along with a little dielectric grease to maintain a good corrosion free connection.

MP

[MPittma100]

Simply Amazing

"I attached the end of the second (battery) ground wire to the ground wire in the tail light harness at the connector under the seat. Guess what? Light problem disappeared! Now, when depressing brake, with t/sigs or emerengency flashers on, the brakes lights are steady and bright. "

did you splice into the harness for that? I am doing mine as i type this and was curious.

A poor ground has baffled many good electricians over time. And still does today. Splicing a direct battery ground into the harness is what made (will make) this cure.

MP

[geniusloerts]

I upgraded to a larger main battery ground cable a few years ago when I did my harness for all the ground ms they all come back to the large cable on the frame side. So the 10ga wires are not exposed to the off gassing of the battery.

I did do the rectifier while I was at it, just didn't do the tail lights at their plug.