Nissan Repair: 2000 4wd, AT,Frontier wont start, frontier crew cab, starter solenoid

Question
We have had no starting problems with our 2000 4x4 Frontier
Crew Cab until now. It is an automatic with an after market
remote start. I was loading a utility trailer with mulch, and had
backed the trailer into the mound, repositioned it and backed it
into the mound again.  When I tried to leave , the truck would
not  start.  When I turned the key, the dash lights came on, the
doors locked, and all the other things that are supposed to
happen, did...except for starting.  I bypassed the starter
solenoid and the starter ran, but that was it.  It was as if it was
completely disengaged.  I tried starting it in neutral with the
same results.  However, when I took it out of park, it popped out
as if it was caught on something.  As a friend towed me home, I
inadvertantly knocked the shift lever into drive, and much to my
surprise, nothing happened!  It did not engage any gears.  This
all happened yesterday, and nothing has changed.  I have heard
of cut-outs if a vehicle rolls, but that didn't happen.  I have
checked all the fuses, switched arouned all identical relays I
could get to, and made sure the battery is good.  Any
suggestions?  Please post your answer, because as far as I can
tell, no-one has asked this question yet.
Thanks, Colin

Answer
Colin,

The aftermarket alarm cuts into the main power feed to the starter and ignition.  If that wire is defective or loose the vehicle will not start.  I had a Corvette that the connection came loose in and it did the same thing as you describe.  Look under the dash close to the column and you will see where the alarm ties in and there should be where you find the problem.