[DanEC]

I think I solved the mystery today. I got my new relay and started taking the old one apart from the fuses. The green wire on the trailer end practically fell off the crimped connector - apparently the wire was partly severed when the connector was installed and finally broke or it's been flexed a lot as I worked on installing everything and broke. The green wire feeds the right side which is where I had the problem. So the relay is probably good and I may hang on to it for a spare. Should finish crimping and soldering the connections tomorrow.