escort x reg 1.6 16 v immobilisor fault?

just purchased this car and noticed when i lock car by key the light below clock does not work. sometimes when key is in barrel egnition it works then goes off after 3 seconds ( which is correct) sometimes once ive drove car then parked and locked car up it works. sometimes when i come back to car the light is very dim or not working at all. is there suppose to be a engine management light on dash when key is entered then turned onto ignition. can anybody help. also squeky front right wheel is it bearings or drive shaft.