Homemade Immobiliser

[FST4RD]

My brother had an old early 80's carby civic 1300cc....
When he bought it it had a home made immobiliser, if you had the ciggy lighter pushed in the car started perfectly fine. If it was popped out or removed the car would turn over as if you were trying to start it but it wouldn't actually start. Bit crafty.
Which wire would you intercept and put a switch on to do this?

[rollaholic]

i'd say fuel pump relay, but on a carby vehicle it would need to be spark related, probably 12v feed to coil.

[FST4RD]

Thats what I thought....

[Voyeur]

unless the guts was taken out of the lighter, it would more likely be the earth to the coil, otherwise the resistance of the lighter, wouldn't allow enough current through for the coil.

[rollaholic]

i presumed he was asking how you would make something similar, not how the original idea worked

[Mr.Phreak]

I imagine he was going to do it properly and switch it through a relay anyway

[method]

Did the car stop when the ciggy lighter popped out