Why is my fuel pump only getting 6V?

The fuel pump finally quit about a month ago. I installed a new fuel pump, but I wanted to hear it run before I put everything back together.

I turned on the key and it wouldn't run.
I gave 12V to the old pump - no dice.
12V to the new pump - runs.
Hooked it back up - no dice.
Checked voltage into the fuel pump relay - 12V. Haven't checked coming out of the relay, but I figured it would either work or not.
Checked voltage at the pump - 6V.
Put 12V on the pump while it was installed but the supply line disconnected - shot gas on my shoe.
Plugged in fuel line, gave 12V - started right up.

Why 6V? Any idea what is dead and why it would fail at the same time a pump failed?

It probably put a strain on the relay and may have burnt a connection in it. Check it out first.

dirty connections add alot of drain

write your representative and ask him.