Thanks for the replies. Since it was fifty-fifty based on the replies, I completely dissected my 1991 LS400 trunk last night. On the passenger side is the Suspension ECU, which you have to completely remove from its mounting to read the sticker on the side that tells you its that module and you are looking in the wrong place, then re-install it.
So the phone was on the drivers side (actually had my hands on it the day while putting my new antenna drive in). There were two connectors (one leading to and one from) I disconnected them from the unit, sprayed in some contact cleaner, and then connected the two together bypassing the phone ECU (and its mute). The speakers all played but a severely reduce volume (except the right rear passenger which continued at normal volume). Next step is to look at the amp and the link connections under the passenger seat. Any other suggestions?