Ground wire

[Msteuer]

Is there any special reason why HD installed a physical ground wire on applications such as turn signals when the socket performs this task as it as always done historically. Was this mandated by the DOT?

[WML57]

Corrosion of the housings, loose fit cause grounding issues, hence the insulated ground wire.

[kd]

Circuits like lights can have grounding issues further on down the line.  For example fork mounted front signals require a circuit to span the steering head bearings.  Anytime a ground path starts to fail the active circuit will search for the next easiest path to ground.  That may be a critical component that shares some other facet with the failing one and now you have bigger problems.  A good example is turning on the left signal and seeing the tail lamp or right signal flashing dimly too.  The left turn current is hopping onto the other ground circuit to find it's way to ground.

[Hossamania]

More ground is better.
Most lighting issues, if not caused by a bad bulb, are ground issues. I would venture to say 90% or more.

[Msteuer]

Valid points all. Nothing more annoying to diagnose than an electrical SQK. Additionally ground issues no doubt account for the majority of issues. Perhaps I'm overly detailed here but I routinely make use of scotch-brite and dielectric. A little preventative maintenance pays off down the road. You guys obviously understand the ins and the outs on grounds. The extra wire? Can't imagine the motor co. going the extra mile without the DOT pushing.
Thanks for your input guys.

[Msteuer]

Rereading my reply, I think I sound like I'm preaching. (An ass) I apologize. I just typed as the thoughts ran out of my head.
Mike

[kd]

   well smarten up.  None of us ever had that happen to us.   

[thumper 823]

About Positive / neg grounds....
From the hallucinatory thoughts archive of clouded memorable memories.
In short,   (argh argh) the electrons flow from the Neg to the pos, an interesting but surprising thought to most people!
However, it does not matter at all but exemplifies both circuits are equally as important.
Perhaps the slimy limy had one thing correct?  LOL
Looking at it from this direction (Neg to pos) perhaps we will understand that ground is much more than that.
It is in fact the other 1/2 the circuit. SO, never feel bad about running an extra ground wire which in reality is a positive wire.
The system will not ever work without both.
carry on.

[FSG]

you seem very positive there Thumper