Immobiliser(?) only lets car start with door open
A couple of years ago my Ph2 GTV (Cobra alarm) started occasionally (once every 4 months) not starting the fuel pump/turning over.
The solution seemed to be go back into the office, have a brew for 15 minutes with the car on the naughty step, return and everything is fine again.
This year however it has now progressed to a point where the above still happens now and again, but additionally 90% of the time the car will only fire up the systems as expected and start if the drivers door is open.
What really confuses me is the times that it works as a 'normal' car should, which I can't find anything obviously different in those situations.
My strongest guess would be perhaps there is something related to the door being closed, that causes a bad earth, can anyone think of a list of things related to the door that could be the cause, puddle lights, door closed switches, central locking, anything else?
Is there a simple(r) method of systematically trying out some of the potential culprits, fuses etc?
Or am i barking up the wrong tree, and perhaps there is one of the relays that is in part of the immobilizer circuit that for whatever reason is getting old and needing some extra current boost that is happening as a side effect
Anyway, I have searched a while and not found anything similar, so anyone elses thoughts on the matter would be interesting to hear