The second-generation Ford Ranger was made between 2006 and 2011.
With the exception of the early PJ (2006-2009) “poverty pack” XL model, most had central locking, keyless entry, and a transponder immobiliser as standard, yet lacked an alarm. The Facelift PK (2009-2011) XL model actually got central locking as standard!
Interestingly the early XL model does have the central locking relays and wiring loom, but Ford simply removed the door lock actuators!

2nd Generation Ford Ranger
You can tell if your Ford Ranger has an immobiliser by looking at the key. If the keyring hole is in the center as shown in the photo below it does not have one.

Ford Ranger XL Key with central keyring hole
If however the hole is offset to the side then there is a transponder chip in the head of the key.
Upgrading central locking in the XL
The locking is a cable system so adding aftermarket locking actuators is not an option. My suggestion is to get genuine Ford ones which will simply bolt into the factory doors, plug them into the existing wiring and the job is done.

Existing locking wire loom in the XL Ranger
I’m not suggesting taking a loan out and going to the Ford dealership (if anyone knows the pricing then let me know and I’ll post it here). There are enough old ones kicking around at the wreckers these days so grab some second-hand ones.
Ford Ranger Alarm options
If you have a Ranger that still has both remote controls you could opt for an OEM upgrade alarm that works with them. However, given that the Ford remote control is separate from the key I’d recommend an alarm that comes with two new remote controls.
The advantage of a remote alarm is that you have much more control over how it is programmed. If you don’t like the Ford Auto re-locking then you don’t have to have it.
I’d recommend an alarm with an immobiliser if you have the XL version.
If you have a canopy on the tray and keep tools in there then a PIR sensor is a good addition to any alarm.
Note: This post is also applicable to the Mazda BT-50 with the same production dates.
Details about 2012> Ford Ranger can be found here…