Had front brake pads changed recently now abs

The pads should have been renewed when new rotar ,s were fitted,check anti squeal plates are still on the back of pads.

The ABS light comes on when there is a malfuntion in the ABS system, not when the brakes are low. On a Ford you more than likely have a dirty sensor or pick up ring on the back side of the rotor. And no you do not have to change the rear drum brakes when changing your front pads but they should be inspected.
Usually you will change 2-3 sets of front pads before the rears need to be changed.

Go to online store reliable they have repair manuals I am sure you will get the solution. Here's the link
Best Manuals

just look for the blackened/burned pin on the rear light plastic connector and sand it down to re-establish a good electrical connection and save yourself $800 big ones on replacing the multiswitch.

as the mot only says the "brakes work"to a certain efficiency,(the tester does NOT check the depth/thickness of the pads),chances are your pads/discs are in need of replacement.the pads have sensors in them for wear depth, so when checking the pads,front AND rear the abs sensors can be cleaned,and if done by a seat/skoda/vw/audi dealer they can put it on the diagnostic computer to give you a definative answer (this is cheaper than guessing) I replace the pads myself but get the car "diagnosed"when any red light shows.

probbably a sensor is deffective or a snapped wire on the front where it moves about with the steering.
Have a nice day.

hi just finnished doing my mates brakes this morning i had to bleed them air had got in hope that helps

did you make sure to pump all the air out of the brake line

there should be adjustment under vehicle looks like bolt attached to cable just back off nut and loosen bolt 

Check the volume of fluid in the master cylinder reservoir. Low fluid would account for an intermittent brake light.
Check to be certain you are not leaking any fluid.
Noises may be from many causes.
Did you "bed" the pads & rotors?