Feedback through CB

I'm trying to sort this before the next time I need it...

Essentially everything interferes with the CB radio, especially the windscreen wipers and washer motor. It crackles horribly whenever the wipers are on.

Also when I have loud music on this also makes the cb crackle in time with the bass. I have an external amp, so it is probably that causing this, rather than the head unit.

Interestingly the interior light also flickers on when the wipers wipe or when I turn on the spot lights.

I can't decide what it could be. It seems to me that anything that draws a lot of power causes feedback on stuff. Does this suggest an earth fault somewhere or something else?

james6546 said:

Does this suggest an earth fault somewhere or something else?

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Yes. It would be worth cleaning your earths if you've not done so already, starting with the main one from the battery.

Also, ideally radio equipment should have it's own power feed direct from the battery (via a fuse), that said, mine does not and I don't get any interference.

sp00k said:

Yes. It would be worth cleaning your earths if you've not done so already, starting with the main one from the battery.

Also, ideally radio equipment should have it's own power feed direct from the battery (via a fuse), that said, mine does not and I don't get any interference.

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The earths were redone during the rebuild, but there was paint on the bit I wanted to earth to, so I might run another one and see if it helps.

The CB is connected straight to the leisure battery, but I'm thinking that as the interior lights flash there is something more going on than just the CB...

Seems like there is a bit of a short going on with at least one of the items you mention. This can result in spark generated radio signals picked up by the CB.

tottot said:

Seems like there is a bit of a short going on with at least one of the items you mention. This can result in spark generated radio signals picked up by the CB.

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Ah, ok. My money is on the spot lights, have already had a relay fail. I'll try disconnecting stuff and see if it still does it.