Hi just a quick one before I drive 50 odd mile to help a mate out lol My mate has a mk4 2.0i that's been stood about 5months at his dad's he has gone to pick it up early this morning and it's got a flat battery so he jumped it off a jump pack it started but when he takes the jump pack off all the warning lights come on then it dies about 2-3min later I am thinking the battery is knacked but should I take a spare alternator too just in case
It does sound like the battery is knackered but would be worth taking an alternator always better to have to much kit with you than not enough.
Once started the alternator should produce enough power to keep the engine and everything else running even if the battery is completely dead. Check the alternator connections, especially the one in the fuse box above the battery
Symptoms point to faulty alternator. I have had this on our own car, after fitting a new battery etc. Turned out it was the alternator. I later understood it is a pretty common MK4 platform problem.
check the alternator cabling too, they often corrode at the battery box end. if left long enough it can melt the box out so that needs replacing too
