earth fault... guide to finding?

Driving to work with lights on, then out of the blue all the other lights flickered on; brake, indicators, fog lights etc.

The flicker became constant. So i switched off my lights and all was well.

When ever i brake, indicate or use the headlights, everything else comes on...sometimes (most of the drive). This includes the associated lights on the dash.

I assume this is an earth fault, but i only finished rebuilding the car last year and everything had good positive earths, so i dont really know what could have gone wrong.

I've had a look to try and understand how i can fault find this. How i can track down whats going wrong, but not having much luck. Is there any good 'earth fault finding guides' or suggestions from you guys for where to start?

Have you got a volt meter?

Could attach the negative to your battery/ chassis/ with some wire and use the positive to see what wires/ junctions etc have a +12 voltage when they're not meant to.

You could work backwards from there

ensure you have a good earth between bulk head and engine and chassis,if unsure just fit some more

A long lenght of wire straight onto the battery earth post then touch it to each thing you suspect while the fault is happening. Don't assume anything as it could be anywhere from the battery lead on. My system has separate earths to the starter, engine, chassis and an earth termial block on the bulkhead behind the dash.