[Steve2444]

Take the wires off the new plug head and see if you have power going to the end of the wires with a meter, if not something isn't connecting under the wire nuts.
If you have power there then it's either a bad/loose connection at the plug head...
Or a bad plug head.

EDIT... turn power off before disconecting wires.

 

[Steve2444]

Are you using a meter to test, or one of those pencil type beepers with a flasher?

 

[Steve2444]

Using this one ...

Non Contact Voltage Tester 12-1000V/48V-1000 Dual Range Voltage Detector Test Pen Adjustable Sensitivity AC Voltage Meter with with LED Indicator Alarm Mode, Live/Null Wire Judgment LED Flashlight, Tools & Testers - Amazon Canada

Non Contact Voltage Tester 12-1000V/48V-1000 Dual Range Voltage Detector Test Pen Adjustable Sensitivity AC Voltage Meter with with LED Indicator Alarm Mode, Live/Null Wire Judgment LED Flashlight in Tools & Testers.

www.amazon.ca

Use a meter, I don't trust those things.