RedJj,
Are you using any of the original speaker wiring from the headunit to the four speakers? If you aren't, then you may have bypassed the audio signal going to the original subwoofer amplifier. The diagram below shows the subwoofer amp is getting it's audio signal from a splice into the signal wire for each of the four speakers.
It also looks like the factory subwoofer gets it power from a wire directly from the fuse block that is powered when the jeep is switched on.
View attachment 306790