flashers scared of the dark

[LordAnthony]

Hello,

When the headlights are switched on, the right-hand flasher doesn't work, but it works fine when they're off.
Any suggestions on what to look for or how to test?

[Mogwai]

I would suspect a bad earth somewhere. A likely one would be the front sidelight/indicator as this earths through the body of the lamp to the wing

[mike.perry]

What year car have you got? If it has indicators and side lights in the same unit then there will be a single black earth wire going to a bullet connector. Check this wire and the connections.

[LordAnthony]

It's a '58. Thanks for the advice. I've had a root around with no success so far but I imagine it's a matter of perseverance.
The only thing that has happened is that when I disconnect one of the many wires I find that the front indicator flashes but the rear doesn't. Also the brake light on the same side is very dull, even when swapped with new bulbs. I'm guessing this is all earth related too.
I think I may need to get a new loom as there are so many wires and connectors under the dash that it's only a matter of time before something else happens.

[mike.perry]

There comes a time when all the wires in the loom are the same colour black and random wires run everywhere, that you have to make the decision to fit a new loom. You can then have all the accessory wiring built in and have the satisfaction of having it made to your specification.