Car Alarms: ignition cylinder, mercedes c280, precise answer

Question
Hello:
we have a 1997 Mercedes c280 that came to us because key wouldn't turn in the ignition.  We had replaced the lockhousing and cylinder. The car started left okay.  Three days later customer couldn't get car started.  It sounds like when trying to start like the alarm system is preventing it from starting.  Car wouldn't turn over.  Can you please help.  
Thank you
J

Answer
Hmmm, Not my area of expertise, so for
this one, I'd like to have you write
to my friend and collegue Robert M.
in my Forum at www.INSTALLSUPPORT@AOL.COM

Please email him and restate this qusestion
& I am sure he will be happy to assist.

He's very good about getting back
to folks quickly

Tell him ALARMTEK
SENT YOU.

If anyone can give you a decent
and precise answer for you on this,
it's going to be Robert.

Good luck.