Need to supress 0.5sec pulse for 0.5sec, then output

[yamajason]

I have a Directed Electronics Passive Keyless Entry, it flashes the Parking Lights for
0.5sec ON,
0.5sec OFF
0.5sec ON
OFF

I want to Ignore the 1st Pulse ON (which signals Locked) and only output signal on the 2nd Pulse (which signals Unlocked) this will Drive a Pulse Timer Relay.

The Parking Light Flashes/Pulses are (-)12VDC with 200ma capability.

What would you recommend?

 

[Alec_t]

Welcome to EP!

The Parking Light Flashes/Pulses are (-)12VDC

Why the negative sign? Are these signal levels normally high (+12V), going to 0V (or -12V) for 0..5 secs?
Are these already-debounced signals, or are they from mechanical switch contacts (and so would need debouncing as a preliminary step)?

 

[yamajason]

The (-)12VDC is really +12V going to 0V ground from a chip. No debouncing required. Manual lists it as (-) output, but you're smarter than that. Thanks

 

[Alec_t]

only output signal on the 2nd Pulse (which signals Unlocked) this will Drive a Pulse Timer Relay.

Does the output signal have to last 0.5 secs too?
What sort of signal (volts, current) is the Relay expecting?

 

[GPG]

Does the central locking have a locked/unlocked indication signal?