Voltage regulator plugged in backwards??

[kc69]

Would this damage the external regulator. I assuming that it would. I was only getting 12.4 volts back to the battery. Alternator was just check and it is good with 90 amps. So, I bought a new regulator, plugged it in like it had been (red wire 2nd one down from top), and still only 12.4 volts. I then unplugged it and turned it upside down (red wire now second from bottom), plug back in, and still only 12.4 volts. Did I "fry" it initially by plugging it in the wrong way? Oh, new battery too.