Cigarette Lighter Working (As Well As Not Working)

[TCGS]

Ok basically I have an 07 Ford Fiesta, I think its the MK6 Silver Style, one or the other

So everything was going well until I bought a new sat nav. Now my cigarette lighter is working intermittently in that it turns on and off, roughly 3 or 4 times a second (ie the light on the adaptor just keeps flashing. I tried it with a dash cam I've got and that does the same, just goes on and off on and off on and off.

So I figure I need a new socket, so I bought one from Halfords and fitted it (which was a pain and now I have to go to ford to get a security code for my radio but that's another story) anyway that didn't solve the problem.

I didn't know what fuse it was to look at, but I reckon if it is coming on then off on and off, the fuse is fine (or it would just stay off right?).

Any ideas?

Thanks :-)

[b1g_dav3]

I found this with a car charger, the problem is it's quite a shallow socket so anything with quite a strong spring in it won't work >_>