Oh, yes. The test consisted merely of checking the resistance for each plug at the relay. Each plug tested the same-- .4 ohms, if my DVM is to be trusted. New plugs measure about the same, though, so the values must be about right. Measured voltage at each pin of the relay socket, and all measured 12 volts. And the fuse is good. My next step was going to be measuring the current to each plug by inserting an ammeter with appropriate shunt between the relay and the plug--one plug at a time. I still have to put together the shunt, and my resistors may not survive the load for long...