Installing a stealth alarm currently. Was wondering if I can use the fuel pump wire as the ignition wire that lets the alarm know the car has been started and will stop flashing the LED. Or is there a better alternative?

Thanks in advance.

 

I don't know the answer to this, but I would say no, with caveats --

When you turn the key switch from ACC to IGN, the fuel pump primes momentarily, then turns off. If your alarm ignition wire is tied into the fuel pump, it will start the arming sequence between the time the ECU removes power to the FP (through the EFI relay) and engine turn-over.

This may or may not work if you're consistently quick, but I would find someplace else to feed the alarm ignition wire other than the fuel pump. I can't see the alarm working predictably (from the operator's perspective) if it's wired this way, but I've never used the FP for this...

If you don't want to get IGN from under the dash, you can certainly tap into any other ignition wire in the vehicle (IGP2 @ the ECU, engine bay, or somewhere further down the harness on the driver's side).

There's no reason you have to get it right at the key switch or fuse panel. I think a lot of the alarm manufactures describe this method of connection due to the way their in-the-box "starter kill" relay socket is wired (+12V from IGN through GWA interrupting starter). DEI definitely does this with around ~12" of wire. Might be a convenience thing for installers on the clock.

 

you want a switched 12V source just to turn off the LED? That doesn't make sense at all.