1997 ford explorer immobilizer

I am unable to unlock the doors on my 1997 (r reg) Explorer. Which obvioulsy mean the immobilizer doesn't turn off. I can unlock the drivers door with ker but as soon as you open the door, the alram sounds. I have cexked the battery in the key fob and the cars own battery. Both of which are OK. Has anyone got any idea.

The immobilizer doesnt let the vehicle turn on.  I dont think it has to do with the door locks.  At the kick panel there is a dark GREEN/ purple wire.  Meter that wire while turning key in door and see if goes from a voltage to 0v.  If it doesn there could be something wrong in the actual door. I am going under the asumption that your are talking about your factory alarm.  unless you have an aftermarket alarm in which all you have to do is remove the alarm harness.

Sorry I should of made it more clear. I can lock / unlock drivers door with key, but the alarm key fob does not work. It is a Ford Built in system. I have tried both of my alarm fobs but neither work.

I'm not sure if the Explorer is any different in the UK, but here in the US, you could have one of two things: 1. A factory-installed alarm, from Ford. Turning the key in the driver's door should shut the alarm off. 2. An aftermarket, Code-Alarm brand alarm, but with Ford logos on the remotes. Other than the logo, this is totally an aftermarket alarm, installed locally, just like any other system. If you see anything non-factory looking under the dash, it's probably an aftermarket. Look for a small pushbutton switch, mounted under the dash, in the driver's left-foot area, or sometimes hanging from another wire harness, or tied in the fuse box. If you operate the ignition switch and the valet button in the correct sequence, the alarm should turn off. It's usually: 1, ignition on. 2, press valet button.....but it could be a little different......if you find the button, play around with it and the key, and the alarm should turn off.