Yes, that quiet high pitched whine is normal in 160s. I had the same problem with iffy relays in mine too. I replaced the fuel pump and headlight ones.
I would say that the brake light micro switch is worth replacing too (thread)
It was a great car, I miss her...
That whine is normal on all the electric throttle cars with the lotus or caterham ecus. Nothing to worry about
Hi Simon did you get replacement relays from Caterham or did you find better quality compatible ones somewhere else?
I just bought replacements from eBay for a few pounds. I think that I simply typed the part number into the search bar.