subwoofer works wired series not parallel

I have a 15-mojo12d2 dual 2 ohm sub and a brz1700.1d amp. Amp is supposed to be able to put out 1700w @ 1 ohm, and sub is supposed to handle 1 ohm. I've wired this sub to 1 ohm before with a 1200w Brutus & a 1000w Memphis, but for some reason, this isn't working. If I wire just one voice coil, it works (tried both this way). If I wire in series the sub works (though, quieter than with just 1 coil). If I wire the subs in parallel, I get nothing. I run 1 (+) wire to coil 1, and one (-) wire to coil 2. I then run a jumper wire from (+) to (+) and a jumper (-) to (-). Is this correct? Am I doing it wrong?

Heres some pictures. Upon testing, it appears I DO have the sub wired at 1ohm, so why is this not working? 1 Ohm when wired Coil 1 w/ no wires Coil 2 w/ no wires

In the pictures, do you have the red meter lead on the positive terminal in each photo.  If so, Memphis labeled the terminals of one coil wrong.

Yes I do. And I reversed them like you said (pre-edit) and now it works. I don't have to worry about one being backwards and frying my sub, do I? I'm guess theres some sort of safety for that and thats why it didn't work? If one is backwards, and I flipped one, which in turn made BOTH backwards, the sub will fire backwards, correct? Like the way you would wire if you were facing the sub magnet-out in the box?

what you did is basically the same as flipping the 180 degrees phase switch on the amp.

while you were having problems, you were powering both voice coils but they were each trying to move in different directions making the cone stay still.

i had a guy years ago do the same thing and left it hooked up for a couple weeks running his system hard most of the time. by the time he came to me it was too late for those woofers enjoy it hooked up correctly. although it made sound, it was awfuland his voice coils being powered with no movement to cool for so long made them get so hot his formers had come looses and fell off the woofers one the fist days or so of being hooked up and able to move.

yuk

quiet rural missouri, near KC.

If your system moves you physically and not emotionally, you have wasted your money.