Set off this afternoon from Hastings to go to Cornwall. Got as far as Chichester before the alternator warning came up, all the instruments went to zero and various warning lights started going on and off seemingly at random

Pulled into a layby, checked the connections & fuses but couldn't find anything obviously wrong. Restarted engine and & no warning lights

set off again & the symptoms resumed. After a few hundred yards the only light still showing was the spanner light &the engine was running sweetly so we carried on. At the next roundabout I realised that the gearbox was in 'limp home' mode (ie 3rd gear) but there didn't seem to be any immediate reason to stop so we carried on to the Rownham services on the M27 and called the AA.
The AA van appeared after about an hour and confirmed that the alternator wasn't charging

made some phone calls and discovered that none of his contacts had a replacement alternator. He put in a request for a recovery lorry & left.

About an hour later another van turned up (no recovery lorry available) & propoed to use one of his spare batteries to allow me to drive to Honiton (the edge of his patch).
I am now sat in a supermarket car park in Honiton in the dark with a knackered alternator waiting for the next AA man to materialise.
Wish me luck
PS anyone know what a new alternator should cost me?