Does the TM4000 radio on 1992 Previa you have a 'Pre-Amp' if so where is it I have tried another working radio but it will not work on the Previa?

Answer 1

It may be under the drivers seat as on the lucida. If changing radio to standard you need to bypass the amp unit and wire radio to speakers direct. This means connecting all speaker wires to the ones that go from the old radio to amp unit. You will need to make a note of all connections as you do them all one by one. Tricky if your not experienced with wiring.