Barrie, welcome to iRV2.com. We are glad to have you join us here. We look forward to reading of your adventures and experiences. I am sure you will enjoy this website and forum very much. I will put in a short cut to the New Members Check-In and Gulf Stream owners sections of the forum so others can welcome you and we can help you resolve the lights issue.
Have you checked for a loose ground? You can always run a new ground if you find one iffy. You may want to also check the back of the fuse block where the relays plug into, you could have a bad connection there. Good luck and keep us posted as to what you find.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7