2001-2003 Honda TRX500FA Factory Service Manual, Page 337Get this manual
ELECTRIC STARTER From page 21-2
Check the starter relay voltage (page 21-10 )
Abnormal -
Faulty ignition switch
Faulty starter switch oose or poor connector contact
Open ci rcuit in wire harness
Check he starter relay switch operation (page 2110)
I- AbnormalFaulty starter relay switch