Horn / steering column ground issue...

[Steve in Jax]

Baffled by this one. Everything about the horn circuit checks and test functions up to the horn button itself.

Horn button and associated plunger all pass bench tests. However a ground from the steering column or steering shaft is missing.

If I attach a ground cable to the steering shaft above the universal, everything works fine. The steering rack itself has a working ground. But, the rubber bushings in the universal joint appear to electrically isolate the shaft.

It does not appear in the manual that any kind of jumper was intended to bridge this. Yet the horn did work in the past. Have no idea what has changed.

Any suggestions? Thanks!

[jcocking]

Here is a past article with pictures.

viewtopic.php?t=40053&p=279228

[ElanDNA]

I think OE assembled it like this.

Urs

[gus]

Replace it with a U joint style. The rubber bushings die and the ground strap loses connection

[s28ven]

I had an issue lately where the ground wasn’t conducive from the top of the uj to the column itself. I had to separate the column from the uj, clean and re-insert before it would work.

[pharriso]

I bought these - https://www.ebay.co.uk/itm/LOTUS-ELAN-PAIR-STEERING-HORN-EARTH-STRAPS/371845048398?hash=item5693b1284e:g:sPMAAOSw44BYg2Ru
Worked perfectly

His postage is the US is rediculous, you could ask him for a better rate...

[billwill]

No one seems to have given you a simple answer, though you can deduce it from the complex answers.

YES, there should be a conducting link bridging the rubber joint of the steering universal joint. The simplest fix is to make you own link as per the picture in the topic referred to above.

[Steve in Jax]

I’d like to thank everyone for their prompt response to my problem. It does appear to be caused by the missing jumper.

I’ve just finished pulling the flex joint. Figured it’d be easier to fit a jumper on the bench and might as well renew the bushings while we’re at it.

Will post an update to confirm if that proves to be the solution.

As an almost lifelong Lotus owner, I think the ideal Lotus mechanic has arms resembling the tentacles of an octopus, tipped with the tiny dexterous fingers of a raccoon, capable of delivering the torque of an air impact wrench, has the patience of Job and is not claustrophobic.

[sveris]

Great description of the Lotus mechanic! If only we had a photo ....

[RichardHawkins]

A long time ago, about 1970 I saw a cartoon showing an advertisement for Lotus mechanic with special attributes.

The mechanic was much as described above, but all fingers and thumbs had hexagonal holes of differing sizes.

Made me laugh,

Richard Hawkins

[prezoom]

And the agility and flexibility of a snake for getting under the dash.

[ElanDNA]

And don't forget to have the disinfectant for all bloody spots at hand ...
Urs

[alan.barker]

And don't forget to have the disinfectant for all bloody spots at hand ...
Urs

There's plenty of that around at the moment.
For the jumper maybe Braid is more flexible.
Alan

[Steve in Jax]

Success!
Want to thank everyone who responded and offered advice and support.
Issue was the missing ground across the flex coupling.
My rubber bushings were shot. I replaced the original unit with RD Enterprises universal type joint. Maybe other sources have them but RD did not carry the original style bushings.
Before installing, I tested for electrical continuity across the joint. Failed to conduct reliably. Installed it with a pair of jumpers.
Horn works great!
Was quite the task removing and replacing that coupling!
Thanks again. On to the endless task list.

[nmauduit]

https://images.lotuselan.net/lel/15779/ ... artoon.jpg