It's actually not for my Blazer, rather my 75 volvo. But none the less, how does one tell if a relay has gone bad? My fuel pump no longer pumps fuel and I'm trying to tell if it's the juice or the pump itself. There are two relays involved, and both have 5 connections. Do I just test for continuity? Do I need to find which connection is the lead in, and which one is out to the pump? As always, thanks in advance.