I want to be be able to immobilize a vehicle. The use case is for theft prevention.
All along I have been thinking in terms of disabling the starter relay, as discussed here, Current from key to solenoid of starter motor relay , however a relatively high current carrying capacity is required which makes the control difficult.
What if I were to disable the fuel pump instead. Does anyone know what are the pros and cons of immobilizing the fuel pump versus the starter relay?
Using the relay to disable key elements of a vehicles ability to run give me pause. Any misstep in the implementation process could lead to a failure of the pump or device critical to the vehicle continuing to run could proved to be dangerous.
I would not recommend using a switch or relay due to the hazard of the vehicle failing to run while driving. A plethora of disastrous situations come to mind that I will not illiterate due to relevance.
Disabling the starter motor through the starter relay with a switch/relay device seems considerably safer. If the device you insert fails, your car will not start. Since it will not be in motion during the failure, it seems like a considerably safer route.
This should be technically simple as you would disable the low voltage side of the starter relay and the voltage will be 12.6 volts, roughly.
If you immobilize the starter motor, then the start motor wont run, so even if you put the vehicle in gear there will be no movement.
If you disconnect the fuel pump, the starter might start and run, if you engage the gear (depending on the vehicle) it may move a little distance too.
Could you please provide little more details on the use case for immobilizing... based on that we can suggest better.
