looks like you need a pullup (470 ohms) to +5V for the wire marked in green, and an NPN transistor with the base connected to the green line, the emitter connected to ground. and the collector connected to the wire marked in blue. the blue wire should also have a 470 ohm pullup to +5V. this will operate the protection relays, but will not provide any time delays that the CPU would have provided. you could use a time delay on the base of the added transistor, but it would need to be strictly a positive edge delay of about 5 seconds (in other words, the speaker relays need a turn-on delay of about 5 seconds to allow the amps to settle after power-on, as well as waiting 5 seconds to turn the speaker relays after a protection trip). in order to protect the output transistors properly there must be no time delay on the falling edge.