O/S Brake light not working

[James McGrath]

Here's another weird electrical conundrum for you.

The O/S brake light has stopped working on my Dad's CD manual.
It's not the bulb as I've tried fitting a new one.

Oddly, if I take the bulb out of the O/S rear indicator, the brake light starts working again.

I thought it might be the indicator relay, so I changed it for a new one but it’s made no difference.

Any ideas on this one?

[Robsey]

Have you checked the wiring and connectors for the rear cluster.?

Sounds like an earthing issue, so the voltage to the brake light is finding another route to ground.

[James McGrath]

I unplugged the cluster and gave everything a spray of contact cleaner but it made no difference. I'll have to have a closer look tomorrow.

[Robsey]

Ideally, if there is corrosion present, it needs to be rubbed or scraped away.

I have seen many cars with mis-behaving rear light clusters.

And every time it has been the rear bulb holders or the connections to the holders.