I am not a ASTRA or SkyTek user so I can't comment on the quality or reliability of these units. The install guide is rather brief. While
it doesn't show a Starter Kill circuit here is one way to do it.
You will need an external 30/40 Amp relay. Hopefully the car in question is a typical vehicle with a dedicated STARTER wire and
Ignition wire easily found at the ignition switch harness. Locate this STARTER wire and make a cut at a convenient location.
Relay Pin 87a to one side of the cut vehicle STARTER wire
Relay Pin 30 to the other side of the cut vehicle STARTER wire
Relay Pin 85 to Astra 777-c Orange (-) 500 mA Armed Output
Relay Pin 86 to vehicle (+) Ignition1 wire ( same wire that goes to Astra 777-c Yellow (+) Ignition In 12V )
Circuit operation :
When the Astra 777-c is not armed, the relay is de-energized and just passes the STARTER signal through. Normal vehicle
operation.
When the Astra 777-c is armed, it is constantly outputting the Orange (-) 500 mA Armed Output signal, however this has no affect
on the relay ( saving battery power ) until the Ignition input on Pin 86 goes to +12V. This happens when the ignition key is turned
to ON. At this point the relay is energized and opens the Pin 87a to 30 connection. When the key is turned to START, Ignition stays
at +12V and with the relay still energized prevents the START signal from reaching the vehicles start circuits ( starter motor ) and
cranking the engine.
Additional concerns :
Cutting the STARTER wire to add the relay could cause issues if the connections are not properly made. The relay should have a
quality 5 Pin harness and the Starter wire connections should be soldered and insulated with heat shrink tubing.
When the Astra is armed and the Starter Kill is in effect, it is possible that the key will be repeated and rapidly turned to START in
an attempt to get the engine cranking. This will cause the relay coil to generate a strong pulse when the field collapses that could
damage the Astra 777-c. A relay coil quenching diode is needed. Obtain a 1N4007 diode and solder it to the Pin 85 and Pin 86
leads with the band towards Pin 86.
Soldering is fun!