John,
I know I'm late on this one, but I concur with everything Peter said. It sounds like the relay.
Gilly,
I'm going to have to go head to head with you on this one. I believe the resistance test is valid 98% of the time. It always works for me. I agree that you do run into some weird situations where resistance is right on, but the system is still problematic. Thaen I would run a current check or better yet I remove the plug and hook it to a battery. I look for the glow. Some of these plugs can trick you, but I find that to be rare.
