1999 lincoln navigator, rsx 3.5

I have all the wires wired correctly and the thing will not start. Do I need a bypass of some sort here? Thank you

yes you will need a bypass. that vehicle uses the PATS immobilizer, the bypass made by DEI is the 556UW

Like azaudio41 mentioned in the previous post you can use the 556uw but you would lose a key.  If you'd like, you can use a KEY-OVERRIDE SL. Just connect 2 basic wires at the connector in the key cylinder and of course your ground, power, ign, and gwr and your done.

or you can use a d.e.i. 555f or 555p so you do not lose a key, just sometimes can be tricky to find a sweet spot t secure the pellet so that it works when all is assembled it is sometimes trial and error, or use a trilogix bypass

to test all your connections and programming, put your key in the ignition, do not turn it on just let it sit there and try to remote start it as it will read the key for the pellet, also forgot to mention in my previous post you must have 2 working keys to enter the p.a.t.s. programming to learn the bypass so if as most older cars do you only have 1 key youll have to get the dealer to make you a second key first then either put that key in a 556u or use the 2 keys to then program the 555f or 555p

the KEY-OVERRIDE-SL distributed by crimestopper and or compustar needs ONLY 1 KEY to program. The link to the bypass is here... KEY-OVERRIDE-SL