I can tell you this much -- all the AM/FM sets have a fader control, and a 4-pin speaker connector. The radio's fader control is NOT used with the reverb. On the four pin connector, one pin is male and the other three are female. If you only have one speaker, you would connect that speaker to the first two pins -- the male, which is ground, and the femae next to it, which is radio output. The remaining two pins go to the fader, which again is not utilized with the reverb.
SoI would look for a two-pin connector to plug in there, and another two pin for the front speaker, as this speaker operates as normal. This output signal goes also to the reverb. The reverb's output should go to the rear speaker. There is also a switch/control that mounts under the dash, and a foot pedal switch.
The object is for the front speaker to play normally, while the reverb, with the switches and the control adjustment, provides an echo sound that comes from the rear speaker.
