UK Car Repair Questions? Ask a Mechanic for Answers ASAP
the main earth wire will be fixed to the negative battery post
so best method is to locate that and follow the earth wire down to see where its fixed to the chassis and the engine
any of these large earth points must be corrosion free and tightly fastened
its also worthwhile measuring the resistance of the earth wire as it should be no more than 1-2 ohms , anything higher than this and the wire will need replacing
do you still need help?
Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. so if my answers have been helpful please rate my answer.