Quote Originally Posted by a2lt16v
i have heard that running the engine earths in the engine bay and allowing it to earth all the way to the rear of the car purely through the body is bad.

it allows the tiny electrical currents to react all over the body of the car and help promote rusting. think is a reaction with the small currents and the damp and the metal probably has a scientific name but i dunno what it is this was discovered on the old minis which is why some people choose to run the earth cable all the way back to the battery terminal.

this might be a load of rubbish tho, but if you think about earth points on cars they are usually corroded and rusty! there may be truth in it
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yeh i agree with that, i was told by an engineering teacher a few years back, its not such a good idea to run the earth that far back, tis why i mentioned it in the first post, he didnt so much say on the lines of what u just said, but i wouldnt be surprised if that happened, he did say something about the time it takes for the current to flow thru the body and back to the front end for proper earthing, plus electrical interference on the way. probably why they put the battery so close to the engine with such a short lead to the body, saying that most bmw's run it way back tho dont they, interesting discussion on the matter tho. depending on how much cable i can get my hands on, ill either use one of the rear seatbelt mounts as the earth or run it back to the proper earth point in the bay, going to gain a little weight with the extra cable, but it might be worth while if its gonna cause running probs or possible 'extra-terrestrial' rust