So I have a ranger that's been sitting for a couple of months. I decided to take it for a spin today and have found that somehow it's now in anti-theft mode. The red padlock symbol blinks on and off on the dash. I have found that if I use my quick-start battery jumping tool it will start, but once I turn it off and remove the key from the ignition it will not start up again unless I repeat the quick-start procedure. I've tried disconnecting the battery for 30 minutes, but when reconnected it still hasn't reset. Any ideas? I dearly prefer not to go to my local Ford shop because they're a bunch of crooks.

 

It takes 90min or so to reset, unhooking battery does matter

Test battery voltage key off
Needs to be 12.3v to 12.8volt, or voltage will drop too low when starter motor is on
New battery is 12.8v
3 year old battery 12.5v
5/6 year old battery 12.3v and time to shop for battery sales
12.2v or lower is a "done" battery

Also test charging system
Start engine, battery should now read 13.5v to 14.5volts, up to 14.9volt is OK temporarily, should be under 14volts after 10 minutes of running
Under 13.5volt means alternator is not working like it should