Cobra immobiliser.

[brianthesnail]

Hi all after some advice on the immobiliser.
Started the car yesterday to start getting ready to do MOT related stuff. Started easily so ran it for a while went on a short run to make sure all was ok and then....

Car cut out and now I cannot disarm the cobra immobiliser usually you press the little black dongle in the port on the column, the light goes out and all is good. Now the light won’t go out, the fuel pump spins it turns over ok but won’t fire. I’m guessing that it is interupting the coil circuit still. Obviously I cannot check for a spark as if it is absent it could be related to the immobiliser.

I have checked through old threads and tried to trace the wires from the contact point into the loom but I’m struggling.

So before I have to revert to getting an auto electrician involved are there any steps I can do to by-pass the immobiliser or is the only way to trace all the wires and remove it completely?

Thanks in advance for any help offered.

[Penelope Stopit]

The immobiliser should be breaking 2 or 3 circuits, there is a possibility that some circuit cuts have been bridged out in the past
An auto-electrician will have to trace the wiring, this is why the job could cost you a tidy ammount
If money is not an issue phone an auto-electrician, if money is an issue you could slowly trace the wiring through
The immobiliser unit is very likely shoved up behind the dashboard, all the cobra cable are black and they run in pairs to each circuit where it is cut, there are also 1 or more wires that connect straight to an earth point, a fused battery and ignition supply
Going at the job slowly slowly will sort it without too much difficulty

[GreenV8S]

The alarm installation on mine was absurdly crude and easy to bypass - to the extent that it probably didn't provide any actual deterrence to anyone wanting to steal the car. I was told it was an OE alarm, but seeing how it was bodged in I wonder whether it was an aftermarket one. It was just spliced into the loom close by the ignition switch, with the control unit pushed up beneath the gauges. By 'spliced' I mean that somebody had literally cut the original loom, twisted the exposed ends of the wires together and wrapped adhesive insulating tape round the join. Obviously not a very durable joint and I'm surprised it lasted as long as it did. It did make it easy to reinstate the original wire, though.

[brianthesnail]

Thanks for the advice. I need to take the dashboard out anyway so I’ll do that and remove immobiliser at the same time. Hopefully I can find time to do that and all the other “little” jobs I have been putting off doing on it!