As explained in the Monsoon FAQ sticky, a head unit has to be able to control an external CD changer in order for the auxiliary adapter to work. All cassette head units were capable of controlling the changer but only CD head units that were from late 99 or later had that ability.
In your case, since you already know that the CD head unit has a changer, the adpater will work with either one of those head units. In fact, if the CD head unit is from an 01 or 02 model then you can add the auxiliary adapter and still keep the CD changer (01 and 02 models had the ability to have more than one external device connected).
White 2000 Trans Am (sold)
White 2011 Mustang Convertible
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