I wired in my Sterling Excel transponder immobiliser today, and all seems to be working well.

The immobiliser requires two circuit cuts. I cut starter motor and fuel pump.

I'm not confident I've cut the fuel pump at the best place however. I spliced the immobiliser to the live feed for the pump, but I'm now thinking I should have cut the feed to the fuel pump relay.

Having had a look at the instructions, the immobiliser wiring and circuit cut relay is rated to 18A, but I don't think the R1 pump will draw this much current. In fact, the R1 ignition fuse is rated at 15A, so my thinking is that all should be ok.

Is my reasoning sound, or should I cut the relay feed instead?

Jek

One of the circuits needs to be a 'live' circuit think they are the white wires.

My 'live' circuit isolates the ECU power supply.

The second circuit operates a relay which in turn provides 12v to the injectors, coil and fuel pump.

As you say the relays internally are man enough. I shouldn't worry if its working o.k.

I always cut the feed to the pump not the relay.

Try and spread the cut. This means not just cutting a wire and then joining the new ends to the immobaliser. Its too obvious. Actually cut a section of wire out.

My choice cuts are pump and ignition. You need an ignition feed anyway so you can make a tidy cut with that. If you allow the starter to crank as normal people will assume it will fire. May buy you valuable seconds as they are cracking it to go and club them over the head!!