Do I need to ground my electrics?

Thanks for the tips n trick re my wiring post guys.

Now I have a question that I suspect may have me shot down flames, but here goes anyhow:

Do I need to 'ground' my wiring to the chassis? Or can I take all ground points from all components direct back to the battery?

I'm thinking that my harness, and all components should work even if it was all connected up on the work bench (ie frame totally removed from the 'system'.

With a powder coated frame and greased up bearings, and stainless bolts everywhere that are also greased up, I have a hard time imagining that this lot will be an effective conductor of electrickery...

Any advice, and / or polite pointers as to why I'm being so stupid gratefully received !!

You must grind off the powder, or paint, where attaching a ground point. A star washer under the terminal is good to use....it bites into the metal and makes direct metal to metal contact between the terminal metal and the frame. The bolt only provides clamp force, and could be a poor conductor itself, thus stainless bolts are OK.

Bringing all ground wires back to the battery is the best possible type of analog ( as distinct from digital) electronic wiring.
This said, such wiring is not necessary. The frame is a good conductor and serves as an "everywhere" conductor. Just be sure to clean all connections down to bare metal, and run a separate ground wire to any frame or engine part isolated from the mainframe by bearings or isoelastics.

Slick

I ran separate grounds back to my battery, but after finishing the job I found that the one ground I ran to the engine actually turned the frame into a ground point as well. I still think it's worth running them separate though.

If nowhere else then an earth wire or some kind of return wire from head to coil or coils outer case or mount so you have good circuit for return of HT spark.
I have large gauge wire from head steady bolt to coil bracket and all fasteners are stainless to avoid bad contact due to rust (I hate the look of rusty fastening to)

Fast Eddie said:

Thanks for the tips n trick re my wiring post guys.

Now I have a question that I suspect may have me shot down flames, but here goes anyhow:

Do I need to 'ground' my wiring to the chassis? Or can I take all ground points from all components direct back to the battery?

Click to expand...

You can do both if you like. You cannot have too many earths.

You can do both if you like. You cannot have too many earths.[/quote]

this is good advice I have done that with my bike and couple of cars I have rewired an it helps greatly with future reliability.

Earths back to the battery is the way ahead, if you rely on the frame, OK until you come to the bits on the forks, then the conductivity of the headstock bearings (or lack of it) will leave you with shite lights and handlebar switching. "Fail" as my kids say.

IF YOU RUN A DECENT EARTH WIRE TO EVERY COMPONENT FROM THE BATTERY yOU WONT NEED TO f;;K UP YOUR POWDER COATING. I once saw a guy yeaRS AGO WHIO DID AND AMAZING JOB OF RESTORINBG A WWII ARMY INDIAN, AND HE HAD REMOVED THE PAINT FROM ALL JOINS IN ORDER TO GET EARTHS TO WORK. That was bloody dumb. See also my comments about wiring up headlamps.

Fast Eddie said:

Do I need to 'ground' my wiring to the chassis? Or can I take all ground points from all components direct back to the battery?

Click to expand...

You can with one of these.
Same old story, most things are only as good as the foundation.

http://www.powerlet.com/product/ground- ... sembly/231



http://www.twistedthrottle.com/powerhub ... otorcycles

http://www.easternbeaver.com/

If for any reason I have disconnected the battery or removed the earth terminal(s) on the frame, when I reconnect them ,I use a multimeter and check everywhere on the frame and engine that I have a good earth(ground)

Put one test lead on the negative (-) of the battery (black lead of the meter) and use the red lead of the meter (meter set to 20 VDC) and check every exposed metal part and you should come up with exactly the same reading of 12.++ Volts ( the same voltage as if you measured across the battery terminals) that way you know your earthing is very good, everywhere.

Also you can use the meter set on resistance measurement, and check between the positive terminal and anywhere on the exposed metal parts, engine, frame etc ,it should show 0.00 on the meter or 'dead short', once again showing a good earth , although won't show voltage reading , as in the first example.
Switch leads on the first test if you have converted to negative(-) earth.
As in previous answers, you can never have enough earths!!!
Regards Mike

Ground everything . Run a wire out of your underwear too just for assurances. :mrgreen:

No Earth No Elicktrickery . :x

I don't use the frame as an ground. I rewired my bike (-ve Earth) last year, and use heavy gauge black wire from the battery, to all the points on the bike that require it, including the Engine grounding point. I'd point out that I've ditched the Zener, in favour of a powerbox charging system. You do not need to use the frame as a return, but obviously if you do, and the connections are all sound, it will work fine.
There are some tales regarding frame earthing, why did some manufacturers adopt a +ve earth system for example? There are apparently some suggestions that this reduces corrosion on the frame, but I'm not convinced, and I'm an Electronic Engineer.

Peter

I remember one of my lecturers mentioning the corrosion thing. No memory of the actual reason.

Should you choose to use the frame, or other painted part, then here's a trick which you may find useful.
Fit a straight straight wire brush in a hand drill and just push it into the hole you want to use as a mount. May help to do it on something junk the first time - turns the end of the brush into a point - every time after you get a nice neat ring rubbed through the paint round the hole. I then coat the connection with copaslip, but no doubt there are other, better choices. Never ever had an earth problem on Guzzi's.
Except maybe on the canbus equipped car.

http://www.amazon.co.uk/Silverline-1903 ... 27&sr=1-41 is the sort of thing, although mine looks a bit more butch.

gripper said:

Earths back to the battery is the way ahead, if you rely on the frame, OK until you come to the bits on the forks, then the conductivity of the headstock bearings (or lack of it) will leave you with shite lights and handlebar switching. "Fail" as my kids say.

Click to expand...

There are earth wires connected to the headlight shell that look after this issue.

Cheers

Grease is not a bad thing re electrical connections. All elec connections should be greased.

Break the connections, clean the connections appropriately - wire brush, whatever - smear some dielectric grease on the connections and re-make them. The grease will reduce/prevent subsequent corrosion. Any grease will work but dielectric grease is less affected by heat and will not run off.

One thing to consider re resistance checking - in high current circuits, resistance can test at 0 on a multimeter but have excessive resistance under load. A voltage drop test is better. To do a V drop test, turn on the component in question - say, the headlight; check the voltage with the headlight on at the battery. Then check the voltage with the headlight on at the headlight itself. Ideally, they should be the same but that's unlikely. It is considered acceptable if lighting shows no more than a 10% drop and motors show no more than a 3% drop in voltage between the battery and the component under load.

As an example of why resistance checking may not be accurate in high current circuits, simply consider the following: If you run a new 18 gauge wire from a battery to a starter, it will show no resistance on a multimeter - which is good. But if you engage the starter, the wire will instantly incinerate due to the excessive resistance offered by that size wire for that circuit. Same thing can happen with lighter duty circuits. On the length of wire runs in motorcycles, one strand of a piece of wire is sufficient to show 0 resistance on a meter but that one strand cannot carry enough current to function properly in operation.

I was trained by the snooty Brit Iron and NOC bunch to use the term Positive Earth rather than negative ground.

Somehow electricity grounding point speeds up the corrosioning factor. Its a live point I guess. Anyone know why :?: ?

Torontonian said:

Somehow electricity grounding point speeds up the corrosioning factor. Its a live point I guess. Anyone know why :?: ?

Click to expand...

Something to do with electro-chemistry....not my forte, but anti-oxidation grease will help. Take all grounds back to the battery if it is a concern.

My plan is to run a big-ground wire from the battery and tie all the ground wires to it neatly, does this make sense? and should I terminate the end of the big-wire or should I bolt it to the coil bracketry??

Vince