hehe- late night, bleary eyed watercooling build, eh? what kind of pump? Is there water in the loop? is it connected to a four pin connector? is the PSU that it's hooked up to connected to the rest of the OC at the same time?
Many PSUs will not provide power unless there is a minimum amount of draw- so if you just hook the pump up and jump it, it won't work
For leak testing, the best thing is to pull a second computer up along side and grab a four pin connector from it to power the pump
once leak tested, then hook everything up to the PSU in the main rig.
Have you tried testing it without the daisy chain in there? those cheaply built connectors can be faulty-of one has a bad connection, then the rest down the line don't work- I probably wouldn't run the pump off of the back of a few fans either- got any more free connectors?- if you're worried about no fans, you should be alright running the loop for a minute without them, but I would try leak testing before turning eberything on anyway- got an old computer around?