New car stereo keeps resetting

Okay so i recently purchased a new philips stereo from halfords so i could play my iPhone etc. The thing is its not saving any of the presets and just resets after i leave it off for a while.

I will turn the ignition on, then turn the stereo on. Then i will turn the ignition off and the stereo stays on for a while. But after around 2 minutes the stereo cuts out and loses power. Then i try to turn it on again (without the ignition on) but it doesn't come on until the car is on and then it shoes it has completely reset again.

Now before you all start saying it; I've swapped the red and yellow wires around, i've fed the red into the yellow wire and still nothing.

So i went down to halfords and asked what they thought and the guy said because my car (Peugeot 206 02plate) has an eco mode the stereo will lose power. So he suggested hucking up the red wire from the cigarette lighter straight to the red wire in the back of the radio.

So i look at the lighter and there are only three wires; Grey? Green and yellow(earth and blue? So i assume the grey must be the permanent live wire and connect this wire to the red wire in the back of the stereo… And guess what! NOTHING!

I'm totally baffled and have ran out of things to check or try.i've also checked all the fuses which are fine and i know this because the old stereo still works fine when plugged back in.

Please ANYONE Help!
any advice would help i really don't want to pay £30 to halfords if its just a simple wire switch
ANYONE?

You have a memory wire, it should be marked with the diagram in the instructions. This wire needs to be connected to battery power, not switched power like the main power feed. You should be able to find a connection in your fuse box, check the diagram for it. Do NOT assume the wires are power by the colors, a test light will ensure that you have a full time power lead.

You may have to find a real permanent live to connect to. A lot of cars have stuff that stays live after the car is shut down, but only for a few minutes. Ciggy lighters, interior lights and so on won't stay live for ever

I had this problem, you need to make sure the memory cable is connected to the permanent power (this is usually red or yellow). I'm no expert but I got the serial number for my radio and googled it, I then found the wiring diagram for it. Using the wiring diagram link the memory cable to the permant cable using a connector block or something. It worked for me.