I was wondering, can a normal vamp feed on someone who is awake, and if they can, how?

Use your vampire's seduction power on them, and when you go to interact, it'll show up as an option.

If by normal vampire you mean vampire lord who isnt in the vampire lord form then yes you can (If you mean just the plain vampires like wat you could be before dawnguard then im not sure) you use vampire seduction on them and then you talk to them and you have the option to feed on them

I was referring to normal vamps who arn't vampire lord and therefore don't have the option in going into a vampire lord form.

A vampire lord thats not in vamp lord form and a normal vampire is the same thing.

Vampire Seduction would be the way, if normal vamps can do it that is... should become available once your reach stage 2 vampirism.

This works just fine.

I think hes asking if the red and black eyed vanilla Skyrim vampires can feed on awake people not the new Volkihar vampires (gold/amber eyed vampires that can turn into the Vampire Lord form)

Too which I can't answer his question since I didn't test it, I became one of the new Vampires very fast, didn't even mess around with any of the lesser vampires in the caves.

There are no old vampires anymore, the moment you install dawnguard all vampires are changed to the gold/amber eyed vampires (Having those eyes simply mean your a vampire, not that you are a vamp lord).

Are you sure?

I loaded up my old vampire character and he still had red eyes...

that vampire woman in morthol..cant remember her name..she works at the inn..calls the town cattle..yeah, her eyes are white..post dawnguard.....Alva i think it is?

Nope I can confirm that I had glowy eyes as a vampire before becoming a Vampire Lord.
And, having now learned that I can use Seduction to do this, Lydia, you are now useful.

Please tell me you are not lying. You have Dawnguard and you still have red eyes!

Yay!