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on the mk1 .. the steering rack doesn't appear to be earthed, as a result of which the horn won't work! If we supply it a good earth all is fine, but it needs to come up the column. If we take the column out and check the splined hub, it isn't connected to earth ..?? does that make any sense ..

I had a similar problem with the indicator bulb on the stalk. Wouldn’t work unless I put a separate earth to it.

Proved to be a bad earth from the parcel shelf mount to bracket to column. Cleaned paint off enough to provide a good earth and all OK.

I think the earth for the horn will go through the indicator switch pad to the brass contact ring.

Could be wrong though ...

Horn ground is through the steering column to the rack. If the rack was fitted with Mk2+ type plastic insulator strips on the U bolts, the horn won’t work properly because the rack is isolated from chassis ground.

iain1967s wrote: ↑Tue Apr 20, 2021 4:20 pm Horn ground is through the steering column to the rack. If the rack was fitted with Mk2+ type plastic insulator strips on the U bolts, the horn won’t work properly because the rack is isolated from chassis ground.

that's the problem, thanks. Take the plastic strips out?

Inner column is also semi-insulated from outer by the plastic bush up top and the felt pad down below. Stuffing aluminium foil between the column inner and outer can help it ground through the column bracket to parcel shelf. Easier than messing around with the rack mounts.

I had this problem and simply fitted an earthing strap to the rack.

D

Dearg1275 wrote: ↑Tue Apr 20, 2021 5:03 pm I had this problem and simply fitted an earthing strap to the rack.

D

Did similar to a Restauration some years ago...

Worked fine and if you didn't know, you would not see the earth cable.

Could that be why my indicator stalk didnt work initially ? I think I added the (original) plastic strips to the u bolts.

As said, I got them working by getting a good earth from the dash tray through the brackets onto the outer column ..

Haven't tried the horn yet

This is probably one of the most common problems when people are rebuilding MK1's. With the preference for thick insulating powder coat when things were originally painted it happens on more restorations than it doesn't. Run a "secret" earth from the column to a good earthing point & all is good.

mk1 wrote: ↑Wed Apr 21, 2021 9:07 am This is probably one of the most common problems when people are rebuilding MK1's. With the preference for thick insulating powder coat when things were originally painted it happens on more restorations than it doesn't. Run a "secret" earth from the column to a good earthing point & all is good.

But it's the inner column that needs to be earthed as it's insulated from the outer column .. so the earth has to be from the actual rack?

I thought the inner and outer were bridged on the slip ring assembly?

timmy201 wrote: ↑Wed Apr 21, 2021 9:38 am I thought the inner and outer were bridged on the slip ring assembly?

Exactly!

johnv wrote: ↑Wed Apr 21, 2021 9:20 am

mk1 wrote: ↑Wed Apr 21, 2021 9:07 am This is probably one of the most common problems when people are rebuilding MK1's. With the preference for thick insulating powder coat when things were originally painted it happens on more restorations than it doesn't. Run a "secret" earth from the column to a good earthing point & all is good.

But it's the inner column that needs to be earthed as it's insulated from the outer column .. so the earth has to be from the actual rack?

Yes. The Earth Connection from the Horn Button is down the Inner Column, through the Rack Pinion, to the Rack body and then hopefully to the Body through the U Bolts or the cradle panel on the toe board.

MiNiKiN wrote: ↑Wed Apr 21, 2021 10:04 am

timmy201 wrote: ↑Wed Apr 21, 2021 9:38 am I thought the inner and outer were bridged on the slip ring assembly?

Exactly!

The Brush and Slip Ring are Insulated from the Column. That's the means through which the Return wire from the Horn gets to the Button, then the Earth Return from the Button is as above.

MiNiKiN wrote: ↑Wed Apr 21, 2021 10:04 am

timmy201 wrote: ↑Wed Apr 21, 2021 9:38 am I thought the inner and outer were bridged on the slip ring assembly?

Exactly!

The Brush and Slip Ring are Insulated from the Column. That's the means through which the Return wire from the Horn gets to the Button, then the Earth Return from the Button is as above.

-daisy

This is good to know!
I have put clean earths all over the place but completely forgot the rack!
Cheers all

So, I made the same schoolboy error of fitting the later plastic insulators to the rack U bolts

After a chat with a fellow forumer, I decided to take an earth wire from one of the steering rack pinion end plate to the battery cable to subframe retaining screw.

A 3 1/2" piece of black wire and two ring terminals - one 8mm and one 5mm. Hey presto, a working horn.

Job done and looks quite discreet.

There are very very similar stalks but non mini which have 1 black wire for ground in the loom! Easy to change the loom from it to set it in the genuine mini MK1 indicator stalk and looks exactly same loom only with 1 extra cable which gives ground ! Then what will be needed is to have a black wire connect from chassis to the indicator black bullet. Solves all.