I will be moving onto wiring before too long, and have basically not wired anything since my Hornby 12v train set 20 years ago.

I have seen lots of mention of 'earth' in posts about switching arrangements.

Am I right in thinking that 'earth' points in kit car wiring are really about routing the current across to the chassis.

And that the -ve terminal on the car battery is just connected across to the chassis.

So the 'earth' connections are ways of completing the circuit?

Yes, in short.

Just look under the bonnet of a tintop (assuming you can see the battery!) there is a whopping big earth/neg lead attached to the body. You just attach to chassis instead. Just make sure the cable is big enough, and the connections are all good with paint/powdercoat cleaned off. Poor earth is a real curse.

Ensure the engine has a good short connection to the battery negative as well, lack of a good connection causes problems starting for example.

Definitely have at least one if not two separate earth straps between the engine block and the chassis. Make sure these connections are via an unpainted part of the chassis to avoid any insulation. Dressing these terminations can always be done after testing the engine runs well. A cheapo multimeter will prove you have good earth between the block and any exposed part of the chassis.

Regards

Chris

quote:

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Originally posted by CTLeeds
Definitely have at least one if not two separate earth straps between the engine block and the chassis.

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Exactly that!

Chris

if you are using an ecu, many (most) sensors usually have an explicit 0V wire to the ecu