Electrical issues.

[MoggyMatilda]

So it started off with an intermittent fuel sender but I’ve now realised I’ve no indicators, horn or brake lights working!?

Where do I even start? Could it be a bad Earth somewhere?

[ManyMinors]

All those items are run through the same fuse, so that is likely to be where the problem lies. The fuse is probably either blown or the connections dirty Actually, the horn is NOT run through the same fuse, so that'll be something else.
One fuse deals with everything ignition fed: Indicators, fuel gauge, wiper, heater fan and brake lights....
The other fuse is just for the interior light and horn which work without the ignition being on.

If in any doubt, I would recommend a new fuse box and fuses. These are cheap and easy to fit - particularly if your car is a later 1098cc model with Lucar connectors.

[svenedin]

All those items are run through the same fuse, so that is likely to be where the problem lies. The fuse is probably either blown or the connections dirty Actually, the horn is NOT run through the same fuse, so that'll be something else.
One fuse deals with everything ignition fed: Indicators, fuel gauge, wiper, heater fan and brake lights....
The other fuse is just for the interior light and horn which work without the ignition being on.

If in any doubt, I would recommend a new fuse box and fuses. These are cheap and easy to fit - particularly if your car is a later 1098cc model with Lucar connectors.

As above. Check all the connections at the fuse box are clean and tight.

[geoberni]

Almost certainly just poor connections, as others have said, check the fuse connections are bright, including the fuse ends, and then examine the condition of other terminations.
It really does depend if the car has ever had a loom change.
I'm lucky, my car's was replace about 23 years ago.

[MoggyMatilda]

Thanks for the replies! Turns out it was the fuses. Dirty connections & one fuse being very loose in the holder. All working for now but I might invest in a new fuse box & fuses just to be sure.

[geoberni]

Thanks for the replies! Turns out it was the fuses. Dirty connections & one fuse being very loose in the holder. All working for now but I might invest in a new fuse box & fuses just to be sure.

Glad you found it.
Back in the day, when most weekends a car owner would be out doing regular maintenance on their Pride & Joy, Fluid levels, Tyre Pressures etc, a periodic check of electrical connections would have been included by the more diligent, perhaps only once a year as a pre (or post) Winter checkup..

They're not mentioned in the 'scheduled maintenance' of the manual, but battery terminals, fuse connections, earth points would have been kept clean. You have to be careful with the application of Petroleum Jelly (Vaseline) though, as although it can keep such connections clean, it's also an excellent electrical insulator, so has to be kept out of the contacting surfaces.

So long as your fuse box spring terminals aren't obviously broken, a good clean and careful restoration of their profile with a small long nose pliers will probably be better than buying a modern replacement with unknown provenance of build quality.