Ok, I decided to go the Alpine 634 route as a replacement for the OEM changer. I got the 634 the ACUALP adapter and the 1304 AInet to MBUS adapter. This is for a '91 NSX. Here is the wierd twist. I installed it (without mounting) just to test. I unplugged the factory changer and plugged the ACUALP adapter into the factory head end plug. Next I plugged the 1304 adapter into the ACUALP adapter and then into the 634, changed the switch setting from AINET to MBUS and voila' ... nothing. No power and the head doesn't recognize that a changer is even there. I rechecked all my connections still nothing. Being the computer geek that I am I started eliminating components. If I don't use the ACUALP adapter it works ! The sound quality seems ok (I don't notice out typical out of phase issues) as soon a I add the ACUALP in the mix ... death. I looked on the package and it does say '92 to '98 honda. Is it possible that they didn't reverse the pins on the '91 ?
Tim
Tim