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Main grounding points.


ajh

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So, some things changed since I took things apart. The negative battery cable has two terminals in addition to the battery clamp and I know one of these bolted to the LT77 before but I don't recall where the other goes. I do notice there are no chassis grounding lugs in place though and I thought that was standard practise. The R380 also does not have the same location for the terminal. Is just bolting these to the stud and a bolt connecting the R380 and LT230 considered normal?

I do understand vehicle wiring to some degree, so I am mostly wondering about Defender specific gotchas. My first instinct is to make a new cable and also connect up to the chassis somewhere by tapping in a stainless bolt and epoxying it in place or similar. (still waffling on which mig

I want.)

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Basically the earth has to be the best possible connection you can get. It has to pass the starter current from the battery to the engine. This is quite considerable on a tdi. i`ve measured peaks of over 300As on my meter. So you are thinking strong physical connection with clean metallic contact between earth cable and gearbox

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On my 110, which is of 1986 military vintage and had a 2,5n/a diesel, there is only one cable going from battery to chassis and one up front between chassis and engine. Nothing on the gearbox. And it starts... :)

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My 300Tdi 110 has a similar earth lead arrangement, which is how it left the factory. One end goes to the negative terminal on the battery and the other has a ring terminal which is clamped to one of the studs on the gearbox/transfer box joint. The third terminal on the lead (a tag with a hole in) is fastened to the chassis by one of the gearbox cross member bolts. The gearbox and chassis terminals have star washers either side of them to help clean the contact patches.

The main starting current is direct from the battery to the engine gearbox assembly, while the lower currents for running vehicle circuits (lights, fan, HRW, stereo, etc) are handled through the chassis connection. My experience has been that the chassis terminal is subject to vibration of the thick cable, which tends to break the soldered joint. The circuit becomes reliant on a poorly formed slack joint, leading to strange earth related electrical faults (stereo turning off when headlights flashed, etc). The solution is to run an additional earth strap between the gearbox and chassis points.

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I think that my v8's earth system had been tinkered with... there was one strap that ran from the engine to the chassis, and one that ran from the battery to a common point on the chassis, and the on to both the gearbox and the rear of the engine. Possibly overkill, but hey, it worked.

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I added an extra strap from the transfer box to the gearbox crossmember on the disco, as after changing the gearbox last year, i had some strange electrical gremlins manifest themselves (speakers clicking when changing to main beam, dash lights going bright when accelerating - that sort of thing). Adding an extra, thick earth strap cured the problem. Doesn't hurt to have too many good earthing points on a landrover IMHO

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My '89 110 [ex-TD] currently 200tdi/R380 has it's

Engine earth cable from altermnator/PAS bracket to the chassis part of the left engine mount

battery earth cable to one of the main gearbox to transfer box joint bolts

group of earth cables on bulkhead near the brake servo [RHD vehicles]

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