Here are two vintage radio broadcasts featuring interviews of John Fowles:
A 40-minute interview conducted by Roy Plomley is available at http://www.bbc.co.uk/programmes/p009mvj0, originally broadcast in 1981. Plomley asks Fowles which pieces of music he would most want to be able to listen to if stranded on a desert island (with clips of the music played), interspersed with a discussion of Fowles life and writings.
2) A 29-minute interview conducted in the UK is available at http://www.bbc.co.uk/programmes/p03m0v2p, originally broadcast in 1992. Fowles discusses his battles with solitude, the pleasing mystery of nature and the major influences–including his late wife Elizabeth–on his writing.
Note: you may need RealPlayer or a similar program to listen to one or both of these interviews. RealPlayer can be downloaded for free at www.real.com.