I will say this about DEI products(viper) and ford cars
as far as remote starts, someone that does not a have a LOT of experience putting them into newer fords (roughly 98 and up) there are a couple of special things that needs to be considered or else you will have constant problems,
first, most remote start systems have a tach wire to monitor engine speed to control crank time. the two most common places to grab this are at the coil or fuel injector (always the wire that is not common) but with ford systems, you CAN NOT use a coil wire, if you do the system will shut down after 1-2 min, you are supposed to go to a fuel injector wire every time. (oddly chryslers are the exact opposite, ford=fuel and Chrysler=coil)
another issue if because viper also monitors engine speed and will shut down if it thinks the motor is revving too low or too high, becuase of the difference in engine speed on a cold start vs a warm motor is almost out of safe range. programming Tach is a little tricky, you need to warm the car up first, then shut it off and restart, then train but slightly revving it a tiny bit higher.
the is also a special way you need to hook up door triggers as to not get false alarms all the time. when the computer falls asleep there is a very high resistance to ground that "leaks" on the wire and the viper is just much more sensitive to voltage changes (basically the same reason LED lights glow dimly when the car is off)
I have installed tons of brands over the past decade and a half I've been doing this, and the only brand in have ever seen anywhere as close to as reliable is compustar. the best day of my life was when we stopped carrying black widow/audiovox systems, well actually their warranty work was still coming back defective. With directed systems, 98% of the time if there is a problem, its installer error.
