Right, I'm going to put my horn wiring back to it's original state and do away with the dash mounted button. So far I've found an earth which runs down the centre of the column and is attached to one of the bolts on the coupling, and the original live feed to the horn, but that's it! What am I missing on the earth circuit? Thanks.
Horn Wiring Queary
- Thread starter TeamBrian
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bluenose
Well-known member
TeamBrian said:
the steering column tube should be earthed. If it hasn't broke off there's a spade connector inside at the bottom of it which you can see from underneath the bus
bluenose
Well-known member
sorry mate I told you arse backward before lol.
Wire should run from the spade on the outer tube to the horn not the chassis.
Then the one that runs down the column should attach to one of the bolts on the rubber donut which connects the steering box to the donut
Wire should run from the spade on the outer tube to the horn not the chassis.
Then the one that runs down the column should attach to one of the bolts on the rubber donut which connects the steering box to the donut
starbiscuit
Well-known member
Yep, you don't want the steering column earthed. At least, not until you want the horn to go off.
The column is isolated from the cab floor with a plastic disc at the bottom and rubber where it attaches to the bracket under the dash.
The horn live wire runs from the fusebox along with the brake light wires etc. across the front panel and through the floor to the positive side of the horn.
The wire from the negative side of the horn runs past the steering box and connects to the 6mm tab on the bottom of the steering column outer tube that pokes through the plastic disc in the metal cover over the rubber steering coupling.
That makes the whole steering column, inner and outer, and steering wheel nut, connected to the negative side of the horn.
The horn operates when the horn push-switch connects the whole steering column to the brown wire that runs through it to the spring-loaded metal ring in the steering wheel.
At the bottom of the column, that brown wire is connected to one of the bolts on the steering coupler that is connected to the steering box. That's earth, via the muck and gears and mounting bolts of the steering box.
So two of the bolts on that coupler are connected to the steering column and *must not* be earthed, and the other two connect the steering box that *is* earth.
I had a bizarre issue on my 1970 bus because the PO had fitted a rubber steering coupler that had metal reinforcement. So the horn sounded the whole time.
Simply fixed with a rubber coupling that doesn't conduct.
But it took ages to find the issue, because that was absolutely last on my list of "things it might be" :roll:
The column is isolated from the cab floor with a plastic disc at the bottom and rubber where it attaches to the bracket under the dash.
The horn live wire runs from the fusebox along with the brake light wires etc. across the front panel and through the floor to the positive side of the horn.
The wire from the negative side of the horn runs past the steering box and connects to the 6mm tab on the bottom of the steering column outer tube that pokes through the plastic disc in the metal cover over the rubber steering coupling.
That makes the whole steering column, inner and outer, and steering wheel nut, connected to the negative side of the horn.
The horn operates when the horn push-switch connects the whole steering column to the brown wire that runs through it to the spring-loaded metal ring in the steering wheel.
At the bottom of the column, that brown wire is connected to one of the bolts on the steering coupler that is connected to the steering box. That's earth, via the muck and gears and mounting bolts of the steering box.
So two of the bolts on that coupler are connected to the steering column and *must not* be earthed, and the other two connect the steering box that *is* earth.
I had a bizarre issue on my 1970 bus because the PO had fitted a rubber steering coupler that had metal reinforcement. So the horn sounded the whole time.
Simply fixed with a rubber coupling that doesn't conduct.
But it took ages to find the issue, because that was absolutely last on my list of "things it might be" :roll:
magoo
Well-known member
Is fixing the horn a bit hit and miss? I haven't been able to find someone who can actually do the job.
bluenose
Well-known member
magoo said:
shouldn't be but depending on what's wrong can mean taking steering column to bits so is a bit of a hassle
magoo
Well-known member
It has been in bits!
starbiscuit
Well-known member
The difficulty is that *any* stray path from the steering column to ground will make the horn sound when you don't want it to.
So you have to get all the insulating pieces in the right places.
And if the brown wire through the steering column is not a good enough ground, then the horn won't sound when you push the button.
There's a lot to go wrong and like all old car electrics, there's an element of black magic to it.
So you have to get all the insulating pieces in the right places.
And if the brown wire through the steering column is not a good enough ground, then the horn won't sound when you push the button.
There's a lot to go wrong and like all old car electrics, there's an element of black magic to it.
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