He couldn't get it to work because he wasn't installing it the right way.
The wires he was trying to interface with only make signals when pressing the lock/unlock rocker switch inside the truck; they do nothing at all when the Ford's OEM remote is operated.
By the way, if this part wasn't clear before: The AM1, even though it's made to operate from your OEM remotes, does not have any kind of radio receiver or antenna. It works by monitoring existing wiring in the car.....
Basically in each door, there's a little motor with two wires going to it. When one of the wires gets a ground and the other wire gets a positive, the door unlocks. When the two wires are reversed, the door locks.
In most modern vehicles, these wires come from the car's body computer, and the computer controls the wires in some way that we don't really know (or even care) how. We just need to know to find the car's motor wires.
So how it works is that when the AM1 "sees" one of the wires make a positive, it "knows" that you've locked the doors, and arms its alarm. When it "sees" that ONLY the driver's door unlocks, it disarms.
It's also (usually) tied into the wire going to the passenger's door motor.....when it "sees" BOTH doors unlock at the same time, it assumes it's a bad guy pressing the Unlock button on the door panel with a coat hanger, instead of the rightful owner using the remote....that's because your remote unlocks only the driver's door on the first press.
So anyway, if I'm not being too long winded: The installer is supposed to find three wires in the car: Both wires going to the driver's doorlock actuator motor, and the unlock leg of the passenger's doorlock actuator motor.
One would think that in the 5-hour timeframe the BB installer had your car, he might have sat down for a few minutes and read the installation manual, or perhaps called Directed Electronics' tech support.....but who knows. I used to work there, and three minutes' peace and quiet to read through a manual was a luxury we rarely had.
So basically, the solution would be for the installer to re-read the manual, and connect to the three wires that 91stt listed. There are no relays required; the product is already made for quick and easy installation.
Anyway, the thing is this: The box stores don't sell add-on alarms like these, and their installers have probably never seen one of them before. I started my career at Circuit City and Best Buy, and I had never even heard of the existence of one of these things until I started working for a dealer expeditor.
So anyway, what you probably want is to find out who does work for the car dealerships in your area. They should be much more familiar with these systems. Where in Texas are you? You'll probably have to shop around for a while to find a place that is willing to install product not purchased from them.
Also, be aware that almost no shop will be willing to tackle this if the Best Buy installer already cut or shortened or "prepped" the alarm to be installed. If he did, make sure you somehow get them to get you some new harnesses, even if the manager has to take them from a similar DEI unit from their store stock.