Open the hood and start the engine, AC OFF.
Locate the AC compressor, should be drivers side front of the engine, below power steering reservoir, with fan belt on it.
Turn on the AC to low, compressor should "click" on.
And stay on.
If not then most likely cause is one of the two pressure sensors has failed or there is a pressure problem, but I wouldn't think the MAX AC would blow cold in that case.
The more common problem on Rangers is the Blend Door, and Explorers, they both use the same setup.
Difference between regular AC and MAX AC is the fresh air door, when MAX AC is selected the fresh air door is closed and the already cooler air in the cab is recirculated.
There is also no temp control in MAX AC, cold is it, lol.
And if you have no temp control on regular AC then that is also a Blend door issue
Google: ford ranger blend door actuator
Lots of info and videos on testing and fixing this common problem
The model years are all pretty much the same setup up to 2012
Last edited by RonD; 04-02-2016 at 11:47 AM.