Hi guys. For some time I've used this board as a resource in fixing my Volvo, but I've come across something that has me completely stumped. The fuel pump on my 740 isn't working and I'd be grateful for your ideas.

I tried the usual methods of diagnosis. Feeling the relay as I turned on the ignition, I felt the first click. However there was no second click of the relay as I cranked the engine (and, of course, no hum of the fuel pump throughout.) I pulled out the relay and bypassed it via a wire run from one connector to the other. I heard the familiar hum of the pump once more; this led me to believe that the relay was the problem.

Suffice to say that I've run through three used relays and one new relay with no results. The spark plugs are firing as usual and I have confirmed with a test light that the fuel pump is receiving no electricity with any of the relays. It all seems to point back at the relay, but I'm using relays that are known good.

Could something be causing a working relay to fail in this way? I'm baffled.