Electrical Problem ~ Horn / Earthing

[Garn 1]

Just finished a complete rewire of a Z1B... I cheated
New Harness and LHS & RHS switch blocks. Everything went well except for the horn.

I checked the voltage going to the horn (brown wire from the main harness) reading was 12.2volt. I found that the horn switch/ button merely completes the circuit by connecting to earth. I ran a wire from the battery earth terminal to the handle bars and pressed the horn button and the horn worked!

My question is therefore, how do I get a separate earth to the handlebars?
I suspect I may need a separate earth to the frame.

RegardZ

[tm53chev]

isn't that ground/earth wire grounded at the battery box?

[kas750]

If it's like a triple the earth return is through the control cables...

[KWACKERZ1]

I might be wrong but the horn earth is through the casing of the switch being bolted to the bars which inturn is earthed by being bolted to the chassis components.
There is no direct earth wire that runs up through to the Horn.
Perhaps your chassis earth on the back of the engine is not clean enough, or your frame is not earthed (too much powder/plastic coating)

Easiest thing to do is stick a meter live on your plus battery and the other meter wire on your handlebars to see if you have voltages.

When you depress the horn switch does it make a contact to earth on the negative lead that goes to the horn.

Does the horn work directly accross the battery?

Is the horn a good one? Sometimes they dont make any noise if the bolt in the center is to tight?

[Rich]

Do your handlebars connect to the wiring harness earth via the headlight shell?
It usually isn't enough to rely on the steering head bearings being a good electrical route

[KWACKERZ1]

I thought about that but as standard the headlight ears mounting brackets have rubber at the top and bottom and the headlight is rubber mounted but has the indicator earth wires going straight into the loom earth run which feeds back to the battery.

Looking at the wiring diag the horn switch has one feed from the horn and the other connection shown as earth!
Its not soemthing I have previously had probs with but checking that the handlebars and switch casing have an earth route should verify this. I might check this out on mine when next in the garage.

[Garn 1]

Thanks for the replies to my query, thus far...
The horn does work when I earth out the handlebars to the battery or engine earth connection.
There is no earth continuity between the handlebars and the headlight-shell, or any other part of bike except for clutch lever.
Note: The cable is not yet connected at the clutch lever.
The frame has been powder-coated. As KwackerZ1 suggests, the powder-coating maybe restricting the main earth at the engine to the frame via mounting bolts etc.
Kas750 has a point regarding earth return through the control-cables. I have still to fit the clutch and throttle cables. That would help 'cause as Rich says at this stage, I would be relying on an earth thru the steering head!

So how do I ensure an earth to these handle bars... without looking too ugly ? ... Maybe when I fit the control cables the problem will be solved!
RegardZ.

[02GF74]

^^^ wot they say - the horn is earthed via the frame.

do you have one or two wires from the horn swtich - can't work out if what you are sayuing is that the horn is erathed to the handlebars, whcih then are insulated via rubbers.

[Garn 1]

O2 GF, the wiring diag for the Z1B shows the horn (as is usual) having two leads to it.

One supplies 12 volts from the battery via a brown wire out of the main harness.
The other is a black wire coming out of the LHS switch block. .

The logic at this stage is when the horn button is pressed, it completes the circuit by earthing, that wire, to the handlebars. which should be earthed somehow via the clutch and throttle cables or generally thru the engine earth to the frame.
RegardZ.

[tricky]

hi, had the same thing happen to me last year, power all the way through horn circuit , but would not work, turned out i had to remove the powder coat off the top yolk/lower handle bar mount, so it could earth out to the chassis, it has worked fine ever since.

[Garn 1]

Horn now works. Thanks to forum!
I agree that powder-coating hinders the earth to the handlebars, However, the control cables when connected, certainly earth the handlebars to the engine. I'm not sure what the original design was surposed to do, as the only way to earth the engine to the handle bars is via the control cables as Kas750 says, or via the head-stock bearings.

RegardZ

[kas750]

Don't ask me how i know

[Rich]

Control cables - Carb rubbers, nylon screw on Z1000A1 clutch worm?

[Garn 1]

Rich, this may take some further thought regarding earthing thru the cables.

You're right about the nylon clutch spiral thread which would tend to isolate the clutch cable from the engine. However, the cable is attached to the steel four-start worm thread screw, inside this nylon bush and it pushes on the push-rod that runs in a metal bearing and contacts the 3/8" ball that contacts the mushroom that contacts the clutch basket. Also, the outer cable of the clutch clutch cable would connnect to the outer sprocket cover.

The throttle cables would be isolated by the carb rubbers. Good thinking!
Regardz.

[Rich]

Run an independent earth up through the plastic sleeving to the handlebar switch and secure to one of the internal mounting (indicator switch / cable sleeve holder)screws and then put this to main loom earth.