97 expedition remote start

Make sure that you need the bypass because some of the expiditions and trucks do not need it. If you dont have the theft light that flashes in the cluster and the key with the bigger head you wont need it.

The difference is the install. The 555F has a small pellet that has to be mounted near the igntion switch. At times it can be a real pain to get adjusted into a position that works well. I've even had some that would work at first, then stop and i had to go back and readjust. Finding that right spot can be a little nerve racking. Before you mount it you have to program it, which can be another pain. I must be fair, i've had some that have worked correctly right off the bat too....

The 556S has a small coil wrapped in plastic which you simply place around the ignition switch near the outer edge. you simply mount it, turn the ignition on for a few seconds, repeat with a second key, then remote start. Easy and done.

Both have minimal wiring, a 12volt wire, and statis wire, and the 556S has a ground. The 555F is a one time use devise, once it learns the code you can never teach it another, while the 556S can learn over and over again...

Thanks very much for that info i guess i will go with the 556s since i've never done it before and i guess it's worth the extra bucks so you don't have to go through all that other stuff. thanks again