Dead electrics

Had a weird problem today. Drove to my shop to load up for deliveries. Loaded, went to start and nothing. No lights, no radio, no horn and nothing remotely like a connection to turn the starter. Put jump leads on from car, no different. Remembered a thread on here about a main fuse, so pinched the car from wifey (quicker than going back to get other van) and sneaked on here during delivery round to find it's location. No help, though I've corrected that now.

This afternoon I looked at my handbook, which shows the main fuse near the screen-wash resevoir. It ain't. Finally found the bugger under driver's seat, a few inches up from the crossmember. Coaxed (forced) the 60A fuse out, continuity. Cursed, scratched head. Cursed again. Went back to battery and traced loom from back to front, no other fuses. Took +ve lead off battery, pulled loom into battery compartment and undid the over-large connector which supplies everything except starter current. Then I noticed the plastic covering was damaged where one of the 2 wires goes from the loom into said connector, investigated and found the copper wire had disintegrated! Much lying-on-the-road later a length of 8mm copper earth wire and 2 terminal blocks bridged the connector for that wire.

Question - is that connector just a connector or does it do something else as it seems very large? 2 cables from the battery to it (green and black), the one I cut into was steel wire, though copper on the loom side. Also, why should the copper have disintegrated there - no obvious signs of arcing or corrosion from a battery, so I'm puzzled unless its a steel/copper thing. Any ideas?

"question - is that connector just a connector"

????! Is that spade a spade?! Not sure I get what your asking pal!

I put mine failing down to ragging it down the back roads with no batter clamp holding it down, but maybe it wasn't the case.

As you've unfortunately found out, I think it powers everything except the big dobbing starter motor feed I guess it'll go to the main fuse block to be sent to everything from main relays to fuel pumps to heater blower to lights etc etc...

Putting different metals next to each other will always cause one of the metals to corrode faster than the other, something to do with the outer electron shells, shared electrons or something or other??!!! Chemistry really isn't one of my wild cards I also bet if you use the this junction of different metals to carry current from a battery etc it will make the corrosion occur even quicker - at a wild guess anyway - electrolysis and all that.

P.S thanks for the main fuse location - I couldn't find it on Ernie when looking before chistmas. Saw it on the diagram, nowhere in reality though.

HighlyJetted wrote:"question - is that connector just a connector"

????! Is that spade a spade?! Not sure I get what your asking pal!

What I was trying to ask is does this 'connector' incorporate another component - a diode or resistor for example as it's over-sized for the job of connecting 4 bits of wire - and why is it even there anyway come to that.

If you were to have a long length of cable to power the electrics under the "bonnet", then you pulled the starter motor and the other electrics from the same point, the resistance of the long cable length would have an adverse effect when you activate the starter motor or large load, e.g. the voltage would drop at the split off point, causing the engine management systems etc to misbehave.

hi pfm this sounds exacly the same as has happened to my van, did you find the fault, how did you fix it, would love to know cheers bones

Yes, as per my first post above, found and fixed with some 8mm earth cable and 2 connector blocks.