In the absence of a manual for your system you'll be best tracing all the wires from the alarm & seeing where they go.
It's common for many aftermarket systems for at least two of the car's systems to be interrupted by cutting a vehicle wire & splicing the appropriate pair of wires from the alarm to the cut ends.
Circuitry inside the alarm is operated by the fob - missing in your case - to complete the circuit.
I've had a couple of systems on mine, the first I replaced as the fobs required were no longer obtainable & currently have one of the Cobra systems.
Might be of help to have a look at the basic Cobra 8510 immobiliser so you have an idea of what goes where - obviously it's the choice of the installer which wires to cut but it's often low tension dizzy wire, a fuel pump wire (electric pump) or a starter motor wire (NOT one of the thick ones!)
If the pic works the paired wires 1 and 2 are the relevant ones.
If you're lucky the installer of yours will have been lazy & not cut a section out of the vehicle wire so reconnecting the ends will be easy.
