I always thought it would go on before cranking to build pressure. I had the pumped hooked up a long time ago by someone else. I find that it only turns on when I crank. I don't know if it stays on when the engine is on because I can't get it to start. But so far its only on when I crank the engine. It that how it should be?

 

I always hook my pumps up to the stock relay, if you're still running an intank pump as well then use the stock relay to trigger another relay for the inline pump.

 

it should turn on for a couple seconds when you turn the key to the accessory spot however since fuel pressure is held in the line it sometimes may not start up since there is already snough pressure in the line.