Upgrade Stock Alarm With a Shock Sensor

Introduction.
I basically followed this
post
http://www.c5-corvette.com/c5_alarm.htm
The only thing I
did different was placing the shock sensor against the drive tunnel –
still effective but much easier that way.
Materials.
You�ll need
a shock sensor. I�ve used a CodeAlram IR-S shock sensor, which I got from
a local CodeAlarm dealer for $30. The sensor has four wires: Black �
ground, Red � 12 V, Brown and Yellow are signal wires. The shock operates
by grounding signal wires when vibrations are detected. Yellow wire has
about half of the Brown wire threshold and it is intended to be used as a
warning signal.
Wires. You�ll need a piece of gage 16 or 18 hook-up
wire about a feet long. Also you�ll need two wires (of any types) to
provide power to the sensor.
Methods.
Open your BCM compartment in
the passenger foot-wall. The BCM module is that shiny box you see on the
left (picture 1). Pick it up and rotate the connectors towards you. What
you need is a pin N 9 in the top connector. The numbering is from the
bottom � so the most inferior pin is N1. Just make it easier � the brown
wire seen on figure 2 is connected to pin N6. The green wire is where
you�ll need to insert your hookup wire. Once you inserted it � you need to
test it. Right above the BCM module you should see three wires wrapped in
the black tape: orange, yellow and black (Figure 3). The black wire is the
ground. Get it out of the pack. To test your pin 9 connection, stay in the
car, close all doors and activate the security with your key fob � the
security light should disappear from your dash. Next, connect ground wire
with your hookup wire, alarm should sound.
If you succeeded this far �
you�re 90% there. Next unwrap the orange wire from the tape, it should
carry +12V. Test it with your voltmeter. Next, supply power to the sensor
from the black and orange wires. Touch it � the sensor should light its
LED. Next connect your hookup wire to either of the signal wires and test
it by locking the car, etc. If it works you�re 95% done.
Positioning
the sensor. I decided that the wrapping it around the steering shaft does
not justify the pain of disassembling all the panels. Instead � you can
just lay it against the carpet and the body of the drive tunnel. Just
slide it under the carpet to the left of the passenger foot well. I found
that even the lightest tap against the windshield activates the alarm.
That might be too sensitive for some of you, but the sensor has a
sensitivity dial so it can be adjusted to a setting that suites your
needs.
Figure
1
[IMG]http://www.seanet.com/~mstanzel/vettepic/securit1.JPG[/IMG] Figure
2
[IMG] http://www.seanet.com/~mstanzel/vettepic/securit2.JPG
[/IMG] Figure 3
[IMG] http://www.seanet.com/~mstanzel/vettepic/securit3.JPG[/IMG]