cooling fan problem?

picasso 2001 1.6 8v temp gauge reads first 2 blocks, dash display flashs stop engine now fan comes on about 4 secs then repeats when running about 1min fan does,nt function properly,have tried new fan switch on side of head,and temp reg switch on top thermostat,can,t fathom it out can anyone help,kenny

KENNY
November 2011