So, to be clear, you have 12 V on both sockets? What else can it be? Did you try the bulbs you purchased on another car or perhaps try another bulb on your sockets? It doesn't make logical sense that your sockets have 12 V and the bulbs don't work. I bought a set of Silverstars some time ago and one was defective and didn't work after I bought it so it's possilbe the bulbs are bad even if they're new.