Indicators & Brake Light Failure.

Hey all.
The brake lights and indicators have stopped working on my 1979 Clubman Estate.
A person at work has had a look and a little fiddle, And he says it’s to do with the ‘common wire’ that he calls it that gives the power to the brake lights and indicator/hazard flasher units.

He’s had a look at the haynes manual diagram for my car. But he’s asked me to ask if there are any other connections, or any thing else coming off that wire. Also, am I right in thinking it’s the top fuse in the bulkhead fuse box?

Hoping these aren’t stupid questions, im trying to get as much info for the man at work really. I barely know how to use a multi meter.
Thanks chaps!

Does your heated rear windscreen switch light up? (test with ignition on)

I don’t have one, it’s a estate.

> I don’t have one, it’s a estate.
Sorry, I should have thought about that one…
Are you sure your hazards do not work? as these are powered off a different circuit to the indicators and stop lights.

Oh really? They dont work, but they may not have worked before the brake lights and indicators stopped.
Isn’t there a wire that goes from the Indicator flasher unit to the Hazard flasher unit? I have I caught the wrong end of the stick.

I hate electrics!