At this point in the remote starter installation, the upper half of the dash is done, but the lower is still all in pieces, with the lower panels gone, various harnesses dangling, the ALDL connector and harness stuffed under the end of the console, and the yellow airbag harness jumping the gap over to the underside of the steering column so I can leave it connected while I'm driving to the train station and back on the weekdays.
As part of the remote starter installation, I have to install a VATS bypass box. This little gadget fools the car into thinking that the correct resistor-chip ignition key was inserted, so it will activate the fuel pump and enable starter cranking. Normally, if there'* no key in the ignition, or a fake key without the right resistor pellet (1 of 15 possible resistance values), the car'* security system will block the starting sequence for about 3 minutes, and light the "Security" warning light on the dashboard.
The box is wired in with the ignition key lock circuit, a loop of wire that the ignition key completes when you put it in the lock. When the box is off, it passes the circuit right on through, so the ignition key can be used. When the box is activated, it cuts in its own resistance value instead, and if you have the right value dialed in, the car doesn't know the difference, and will fire right up.
In the cables coming out the bottom of the steering column are a fat orange one and a fat yellow one. The yellow is the airbag; need to leave that alone (or at least unplug it). The orange is actually a sleeve containing two tiny white wires for the circuit that goes up to the lock, through the ignition key and back down again.
With a razor knife, slice open the orange "wire" along its length to reveal the two thin white wires inside. Wires from the bypass box are spliced into one white wire and physically cut into the other one (forcing the circuit through the bypass box). Until it'* activated, the box allows the circuit to pass straight on through; when it'* activated, it interrupts the circuit to swap in its own resistance in place of the missing key.
This part went pretty easily, except the tiny wires (less than 18 gauge, maybe 22) are a royal pain to fiddle with, and connections must be soldered, since the whole point of this is to get the resistance value through the box to exactly match what the car expects to see from the ignition key.
Need to use a test meter to identify the resistance value of the chip embedded in my ignition keys, match that to a table of resistance values shown in the manual (check Page 4, the fifth page of this file for the listing: http://www.bulldogsecurity.com/pdf/Model781.pdf
), and set 12 dip switches in the bypass box for the correct value. (Found out later that the local Ace Hardware store has a VATS Key Interrogator that makes the job a lot easier: Stick key in the Interrogator, press a button, and one of fifteen LEDs lights up to tell you which resistance value you have.)
Used 4 nylon strap ties to attach box to lower dash support behind subwoofer panel. All connections made at last, and we move on to work on the power lock and trunk-release circuits in the door panel, where a minor disaster will strike very soon in our next chapter...