Thanks Mike + Nigel.
Current situation is this; I've just gone back to the car, turned the key in the ignition - radio comes on and the speedo lights up but there's simply no juice in the battery - when I turn the key the radio & any other lights that are on instantly go off.
So on the face of the battery currently has no life in it, but I guess the catch-22 question is; do I have a dead battery that isn't holding the charge that the alternator gives it, or do I have a dead alternator so the battery isn't being charged? Wonder how I crack that question without forking out for a new battery as a test.
Meantime I'll check your cables / fuse box etc suggestion Mike.
Thanks again both.
first off recharge battery over night before buying something you dont no you need for sure, so battery on charge 16amp or 20amp depending on charger or if a 1amp one then it will take a day and half, after battery charged put volt meter across it 12.8volts will indicate a battery holding the correct voltage, then put battery back on car, put voltage meter across battery while some one cranks over the car ie trys to start it, voltage should stay 12.4 to 12.8 volts and after cranking should come back to 12.8 volts if does not battery is either weak or totally bin time.. so done all this and battery is strong then run car with multimeter on voltage across battery with engine reving at 2 k you should have 14.7 volts for a perfect charge if under 13.8 rectifier in alternator prob faulty replace that or alternator.. if voltage jumps all over the place zero to 14.7 brushes are more likely at fault, if voltage is over 15 volts regulator is at fault new one or alternator,,,
if car is discharging the battery over night, remove the positive terminal off battery and wire the voltmeter positive to battery terminal and negative to positive cable with multimeter set to amperage this will show any discharge from car it should show around 250 milliamps ie car immobiliser, you will before make a reading need to wait for the car to shut down its ecu's ie lock car up bonnet down etc to get a true reading.. if find 1amp to 20amp discharge reading first place to disconnect is alternator as the diode fails on them and allows voltage to drain back,, ie diode only should allow current one direction,,, then remove one fuse at a time to find the circuit the discharge lives on,, or simple diagnostic tester autocom cdp+ or inpa
MY DISCLAIMER TO ALL IF ANYONE READING THIS CANT UNDERSTAND OR THINKS ITS TO COMPLICATED AND CANT UNDERSTAND WHAT I'M SAYING,,, THEN PLEASE TAKE IT TO A MECHANIC WHO DOES,, i only say this as have had a couple of people have a pop about my indepth points on how to repair something because they could not understand it to check if i'm telling the truth,, dear of them