help! main fuse or what?

hey everyone, was just tightening up positive feed at battery and accidentally touched the wrench to the body... spark... now she's dead. checked fuses under drivers seat with volt meter and they are okay, and in middle of dash, can't find anything. thoughts??!

this kind of stuff only happens when you need to pick up the inlaws at the airport in 3 hours...

what is it yr driving, I thought the defender fuses were in front of the gear stick??
theres another fuse box under the bonnet on UK models, 300tdi (&200 I think) on the right hand side(front the front) of the bulkhead.

next time, connect the +ve first, then, if you touch the body, theres no circuit to short, and when you do the -ve, it doesnt matter,

sorry, 03 td5 defender...

and yes, it was completely stupid. was just snugging it up...

ah, no idea on fuse locations on them, still possible one under the bonnet somewhere, look for a black box with a snap on lid.

when you say dead, is it nothing at all, no dash lights or anything?

Yeah the only fuses I know of are under the seat (all the big, main ones) and then accessories in the middle of the dash.

And it's dead, so signs of life, no lights, nothing... Just tested every fuse with an ohm meter and they all checked out. There must be something elsewhere that's expensive and generally unobtainable.

Have you got an immobiliser fitted?

no immobiliser...

I must have broken the turbo encabulator in the engine bay.

Seriously though, I would think testing the main fuses under the seat with an ohm meter would pretty much tell me that they are alright. And i've tested every fuse. So there's gotta be something in the engine bay...

It seems to me that most of the current would have gone through your spanner, straight from positive terminal to seatbox and back in via the negative terminal. It would stress the battery itself a lot more than the fuses and electronics (though they can be sensitive). Is it still delivering in excess of 12V at the terminals? I've found sometimes with elderly batteries that a sudden current draw can result in a substantial loss of voltage. If there's any juice at the battery, can you detect 12V getting into the fuse boxes? I assume that as you're testing fuses you have a meter to hand.

Yeah both batteries are only a few months old and are both showing 12.5 and 12.7 volts. I have a stock LR split charge system, so perhaps it blew the voltage sensitive switch or something else. I guess that sounds like the obvious culprit but I'd have though there was a fuse or something first.

I tested the main wires under the driver's seat, next to the fuse box, and those are showing 1 volt or less. Would those be hot with the ignition off?

You're right - it does sound like a main fuse has popped.
Ive no experience of TD5's but i'm sure there will be a fuse box under the bonnet.
I would start there

Do any of the electrics work???

Daz

Is your battery box under the passenger seat, and does the +ive go into a connection box at the front end of it?

If you have one of these, are the links sound?

yeah, everything is kaput. no signs of electrical life anywhere.

The two batteries go into a voltage sensitive relay AMR3325 I think, and then a little black box also next to that, which I think is another relay. Checked everything and it looks normal. Not sure how to bypass the split charge system either, which frankly is something I probably should know given that I live in the 18th century here (Nepal). I guess I could try to write down where all the wires go and then remove it all and just take the main positive and main neg and hook those up, see if that works...

I thought a fuse would only blow if the short was down stream of the fuse, if you shorted it directly at the battery no current would flow through the fuse but directly through the spanner to the ground, I would try another battery on or maybe even jumping it, although I'm not sure how your split charger will effect it, can you try connecting just one battery up direct to the battery cables?

You could have trashed the battery completely by shorting it. Try measuring the voltage and then turning things on. It may show 12volts until you put load on it and then drop to next to nothing.

Well, thanks for the suggestions, it's still dead though. There's 12v at the alternator and the starter motor. The ground is good under the drivers seat (next to the fuse box), but there is no power at the positive there. Dunno if there should be either. I tested the relay that the positive is fed by to that and it checks out, but there's also no positive at those load wires (that go into the relay)... If anyone has any advice of what I should test, where there should be positive I'd be grateful. I also tested for power entering the ignition switch, and there is none. Somewhere the positive is getting cut out...

jhealey - this is a stupid suggestion but I somehow managed to muddle the terminals on my battery and got no life out of it like you - Have you put it back the right way?

In addition - It's fine now I've put it back the right way (51 TD5) but the radio doesn't work

Well I've determined that the positive to the main wiring harness (under the drivers seat w/ the fused links) from the battery is dead, and that's why the truck shows no electrical activity apart from having 12v at the starter and alternator. So not sure why that is dead yet, but suspecting it's the voltage sensitive switch or the other relay thing that's part of the stock LR split charge system. But really I have no idea, and of course I have no schematic for the split charge system. It's late now here so I'm calling it a day. At least I know it's between the main wiring harness and the battery + connection. That may lead directly to the split charge system, but have yet to figure that out. I do notice that there are no fuses visible in the battery box. I would having fused leads to these relays would make sense, but I'm certainly no electrician... although I'm getting a lot closer after this mess.

As for your radio Aidan88, I'd check your fuses for it in the center panel if it's a td5.