So, am I understanding correctly that your Power Nozzle runs when the vacuum cleaner is turned off but won't run when it is turned on? If so, there's definitely something mis-wired somewhere and most likely it's in the vacuum cleaner itself because that delivers electrical current to the hose, which in turn delivers it to the Power Nozzle.
If you have a multi-tester (also known as a volt-ohm meter), you can easily test your hose to make sure power is getting from one end to the other. Turn your meter on and set it to the "Ohms" setting, which may be marked with the Greek letter Omega. In this position, the meter will respond if you touch the test leads together or if the leads are in a closed circuit. Touch one test lead to the machine end of the hose and stick the other into one of the female contacts on the handle end. If the meter doesn't respond (i.e., stays on 'zero'), try the other contact hole. If there's a power switch on the handle end, which most third-party hoses have and no genuine Electrolux hoses have, make sure it's in the 'on' position. repeat the test with the little flat contacts that come out of either side of the machine end. The meter should respond with a test lead in one hole on the handle when the other lead is touching the flat contacts and in the other hole when the other test lead is touching the chrome part of the machine end.
As to whether the hose is genuine Electrolux, if it doesn't say Electrolux on it, chances are it isn't a genuine Electrolux hose. Also, for whatever reason, most third party hoses have a power switch on the handle that turns the power nozzle off and on. Genuine Electrolux hoses don't have this feature. If your hose has a switch on the handle, it's most likely third party and you need to make sure it is in the 'on' position for the Power Nozzle to operate. Last fall, when I found my Diamond Jubilee canister at a thrift shop, I almost didn't buy it because the Power Nozzle wasn't running when I turned it on. Fortunately, I spotted the switch on the hose.
