Thread: 300tdi Engine Earth

Doesn't the Positive + lead go to the starter, the Negative - goes to a bolt on front of engine straight across from the battery. On the pass. side there should be an earth lead from block to chassis, I believe there is also an earth lead from the starter bolt to the chassis and another from the chassis to the body, Regards frank.

Originally Posted by Fausto79

Anyone know where the engine block earth is on a 1996 disco 300tdi? i have looked everywhere for it. cannot find it. the only one i see is from starter to chassis. the neg feed on battery also goes to the starter.

trying to hook up my madman system but i cant find where to earth it to the block. also there is no earth to the tcase as stated one some other places.

any ideas as to where i can hook up the little earth wire to the block?

The starter to chassis is it, as standard. I also (and many others her so I've read) run an extra earth from battery neg terminal directly to the block, wherever is convenient - plenty of spare nuts and bolts all over the place - I use one on the front of the timing cover as its reasonably close. What doesn't apper to be standard on yours is for the neg to go all the way to the starter - sure its not the positive?

Originally Posted by Fausto79

trying to hook up my madman system but i cant find where to earth it to the block. also there is no earth to the tcase as stated one some other places.

any ideas as to where i can hook up the little earth wire to the block?

For my madman, I used one of the 3 bolts that hold the cover on the AC compressor - not ideal as it goes through ally housing before the cast of the block, but it worked fine and easy to move out of the way when working on it.

The bolt that holds the dipstick tube on - beware heat from the manifold
There are a few bits bolted to the block on the drivers side that don't have huge torque on their bolts - vac pump, fuel lift pump, crank breather, to name a few.

could be positive. was last week i looked. but i couldnt find anything onto the block itself though. just wire running from batt to starter and then from starter to chassis.

i have to pull some ancillarys off soon anyway as i have a big project coming up. doing head gasket and ended up getting a turner performance head. when this is off i will have more room to look around and decide where to go.

i tapped into the cig lighter fuse as it is an ignition on source, it goes to a mini fuse box where i have my engine saver hooked up. i will have another for the madman and another for boost gauge. the fact that there are a few instruments coming off the same power source? will this affect the madman readings? from what i hear they are quite sensitive but all the gauges take up barely any amperage so not sure if ti would make a huge difference. dont really want to start cutting wires etc. i like the fuse taps.

Yes they are very sensitive to other acc on their circuit, when I initially installed mine (off a vacant fuse in the main fuse panel) you could trigger the oil pressure alarm just by winding the electric windows up.

Direct feed from battery (via a relay) helped a little, earthed direct to engine helped the most. Earthing direct to battery or factory earth leads did not help at all.

Originally Posted by SSmith

Yes they are very sensitive to other acc on their circuit, when I initially installed mine (off a vacant fuse in the main fuse panel) you could trigger the oil pressure alarm just by winding the electric windows up.

Direct feed from battery (via a relay) helped a little, earthed direct to engine helped the most. Earthing direct to battery or factory earth leads did not help at all.

so you have the positive wire from ems going right to battery and that wire goes through a relay which is activated by an ignition source wire? so the power from battery only comes when the ignition is on and relay on?