Telstar 85/AR Pioneer Radio wirings

[Flokos]

Dear all,
My original Pioneed radio/cassette unit KP7200zf (red marker moving on preset visually radio stations / large push-button memory mechanism) malfunctioned: chewing cassette tape and I've replaced it with a Pioneer KE5000 (ARC PL Synthesizer, digital radio station display).
I've connected its black to negatives of speakers, its green to pos1 speakers, grey to pos2 speakers and its blue as ACC Power Supply via 3Amps fuse and noise suppressor box. The remaining cables are red (no voltage indicated) but has noise suppression unit, and orange (via fuse) showing 9 volts.
With ACCES key positioning, radio stations were preset and memorised but the following day, memory settings were lost.
Question 1: What's the function of the radio's red and orange cables? I suspect that either could play a role with supplying current for restoring memory while ignition key is OFF.
Question 2: Have I wired the above incorrectly?
I have no schematics of the installed Pioneer unit unfortunately. Thanks, Flokos