That sounds about right. However it did start working again for a few hundred kms so I guess it started as a glitch and then got worse.
Although the relay should be 30 amps (guessing as it isn't here to look at) and the fuse protecting the circuit is 10 amps. Still could be it though. It is a 14 year old relay.
We did try to check amps originally but both Blknight's and my multimeters have blown fuses in the amp feature (I think mine is more than a blown fuse actually).

