'92 GMC Sierra fuel pump not running
 

Replaced fuel pump several years back, truck barely driven since, started occasionally no problem until now. Relay not activating. Removed relay, connected 12v, checked operation with ohmmeter, fine. Fuse fine.

Relay socket unplugged, checked voltage... A to Battery Negative, same as battery voltage, ignition ON or OFF.

This may be irrelevant, but...
...Ignition OFF... A to F 0.5 volts less than battery voltage.
...Ignition ON... A to F 0.2 volts.

No voltage on D (shouldn't there be with ignition on?)

Maybe I'm missing something, but tried applying 12 volts directly to E, pump didn't run.

PLEASE HELP!

So have I baffled everyone? No help?