I got the 2007 Ranger last summer, with the arrival of cold weather I have encountered an issue with the key failing to operating the ignition interlock.
The interlock light on the dash starts flashing as soon as the key is put in the switch and of course the truck will not start. If I put the key in my warm pocket for a few minutes it works fine. I have searched and there does not appear to be a battery in the key so I am stumped as to what causes the problem. The local dealer wants to sell me new keys at $200 each so that is not an option.
Any ideas or suggestions?

 

The key does not have a battery, it uses RFID(radio frequency identification), when you turn on the key switch the computer sends out a Radio Frequency "blast" from the antenna around the lock cylinder(the wand), this "blast" gives the RFID tag inside the key enough power to send out its ID number, computer reads this number, via the wand, and looks at it's list of the 2 or 3 key numbers programmed into it at the factory, if the number is found then engine will start.

These keys for some reason can start to be hard to read, shouldn't happen but it does.

But yours is still working, all be it intermittently, a less expensive option is to "clone" your working key.
Many Locksmiths have writable RFID Ford blank keys, they can "read" your key to get it's number(ID) then program 1 or 2 or ?? other keys with that same number(cloned).
Then cut the key to fit your lock.
This can be done at their location, but having the truck outside to test if it works would be best.

Call for local prices on this.

The above assumes the key is the problem, and since you don't mention trying another key I also assume you don't have another one to try, if you do then use that one to see if it is a key problem.
If not then first step would be to clone current key and see if that helps, if it doesn't then could be a "wand/wiring" issue or computer issue.

Some locksmiths can also add new RFID keys to your computer, this would be more expensive, as they need to hook up their computer to your trucks computer to do this.
This is usually only done when someone loses their last RFID key and it is either call a mobile locksmith or have truck towed to a Dealer to have another key added to the list.

 

Thanks RonD, I do have 2 other keys, I have been using the one that is least worn, once I started looking closer I realized the one I was using did not say Ford on it, the other 2 do.

It is very cold this morning so I took all 3 keys out to the truck, the 2 Ford keys worked fine, except they are worn and need to be juggled to get the tumblers to fall, the other worked the tumbler fine but would not work the RFID.

So you helped me find the problem, I will stop at a locksmith and get new keys cut and programmed and hope that fixes everything.

Thanks for your help.

 

Good work finding the problem.

If you have 2 working Ford keys then you can add a 3rd, 4th or more keys to the computers list yourself.

So lock smith just needs to cut you new Ford keys, cheaper option

To do this you need to have 2 working PATS keys with different ID numbers(so clones don't count), with 2 keys already on its list the computer knows your are most likely the owner, most likely, lol.

Here is a video that explains how to do it: