Viper 791XV won't start

Hey guys, need your help.  I installed the 791 XV in my 02 F-150 a couple of weeks ago and everything was working fine except the remote start.  The truck would crank but won't start.  I would put the key in the ignition and remote start the truck and it would work just fine.  In this forum I learned about the PATS system and I bought the 555F Bypass and tried to install it today but now it won't even crank at all; the accesories turn on and I can hear the clicks but that's all.  Does anyone know what can it possibly be?  I installed the 555F's red wire to 12v and the blue wire to the blue/white - output wire in the H3 harness and followed the bypass instructions.  Did I tripped anyting?  Did I used the wrong - wire? Is there a way to reset the alarm?  I would appreciate your help alot. Thanks!grc

use the 556u instead.

Great advice Reeceddogg.    Possible you unplugged something while you were adding in the 555F? Check the ribbon cable that connects the alarm brain to the relay pack. Make sure it didn't come unplugged some. Also check the two 30 amp fuses on the main power wires of the relay pack. One of them may have blown.

both units take finess. when using the 555f you need to install pelet take both keys turn the key on until you see security light go on take that key out then put other key in and do the same thing. then try to remote start vehicle. that pellet as to hit a sweet spot so it will more than likely take many tries to get it good. both units only require two wires. however both units require a sweet spot in the possitioning on the key cylander as close to the top as possible allowing the pannel to still fit on. with the 555f you have a pellet. witht he 556u you have a ring you have to place around the key hole. placement is key you have to hit a sweet spot. when the bypass system is not located well or you have not learned keys porperly the problem with not even cranking is normal.Jon

Installer/Help Technician

---coral springs florida---

mecp certification is not always needed. I have it and it has not helped me out at all. my experience out shines it.

The 555F may give you a bit of trouble..they are very sensitive. But they do work. ~The Rookie~

Rookie of the year that is...

Don't let the smoke out of your equiptment..it doesn't go back in.

Thanks every one, I'll keep on trying with the 555F now that I know that the "not even cranking" is normal.  I'll keep you guys posted.grc

cantur77 wrote: Thanks every one, I'll keep on trying with the 555F now that I know that the "not even cranking" is normal.  I'll keep you guys posted.

The "not even cranking" is NOT normal. At least on most Fords it is not. Most Fords ( I believe your truck included) will crank, and crank and crank without starting when it doesn't see a proper key (or bypass). Remove any bypass away from the key cylinder area. Put a key in the cylinder in the OFF position. Try remote starting the truck. If it doesn't crank, you have other issues.