I spent three hours installing a TST-507 TPMS in my '08 F-150 Screw. At least one hour was spent just locating the wires to hardwire the monitor to the truck (I tapped into the power lead and ground lead going to the rear power window so there would be power going to the monitor only when the ignition is on), another hour routing and connecting the wires, then the last hour setting up the system. If you want the blow by blow, including pictures, on the installation, you can read it here:
http://www.f150online.com/forums/electrical-systems/513520-power-source.html#post5214488.
For some reason, my sensors didn't want pair up with the monitor at first but I eventually got it done. Setting the high and low pressure drove me crazy at first (that was where I wasted the most time). The first tire pressure setting you come to is the high pressure alarm. My truck's tires are supposed be inflated to 35 lb. so the high pressure alarm needed to be set to 42 lb., roughly 20% above 35 lb. However, every time I got it down to 100 lb., it would roll over to 185 lb. I went nuts reading the instructions over and over until I finally figured out the high pressure alarm setting can't be lower than the low pressure alarm setting. So I scrolled through to the low pressure setting, set it to 31 lb., roughly 10% under 35 lb., then scrolled on through back to the high pressure alarm setting and was able to lower it down to 42 lb. (TST really needs to change the order of the high and low pressure settings). I had to do this for the steering axle, the rear axle, and the spare (I used one position on the second axle position on the monitor for the spare). I left the temperature setting at 158°F.
It took a few minutes for the monitor to start reading all the sensors but, once it got there, the reading rotates from tire to tire every five seconds.