If I'm not mistaken, those old receivers had "multi-zone" and not necessarily full zone 2 capabilities. Multi-zone "on" was to send a multi-zone input code(ie. CD), to turn off I used an unused input such as "multi-zone" phono or tape.

Here is the hex for 3802 multi-zone, give em a try(I don't know if these work, I got them out of my RTI library):

On

0000 006D 0000 0020 000A 001F 000A 0047 000A 001F 000A 001F 000A 001F 000A 0047 000A 001F 000A 001F 000A 001F 000A 001F 000A 0047 000A 0047 000A 0047 000A 001F 000A 001F 000A 06E0 000A 001F 000A 0047 000A 001F 000A 001F 000A 001F 000A 001F 000A 0047 000A 0047 000A 0047 000A 0047 000A 001F 000A 001F 000A 001F 000A 0047 000A 0047 000A 06E0

Off

0000 006D 0000 0020 0009 001F 0009 0047 0009 001F 0009 001F 0009 001F 0009 001F 0009 0047 0009 001F 0009 001F 0009 001F 0009 0047 0009 0047 0009 0047 0009 001F 0009 001F 0009 06DF 0009 001F 0009 0047 0009 001F 0009 001F 0009 001F 0009 0047 0009 001F 0009 0047 0009 0047 0009 0047 0009 001F 0009 001F 0009 001F 0009 0047 0009 0047 0009 06DF

Good Luck