I'm not sure I understand? Are you saying the dimmer switch switches from bright to dim by itself? Are you talking about daytime running lamps? I have seen a faulty battery and or cable cause the headlamp intensity to brighten and dim. Any faulty electrical circuit might cause that. I can't say for sure, one way or the other, that your fuel pump module is the problem? Give me a minute, I'll find the diagram.
Any applicable trouble codes? Has any work been done on the vehicle lately?
November, 20, 2012 AT 5:42 PM
I looked at the wiring, there is about a dozen focus listed for that model year, not sure which focus you have? I looked at ZX3 S focus.
November, 20, 2012 AT 5:44 PM
My bad, hit the wrong button. Diagram. There is also the fuel pump relay, couldn't get that in the same picture.