Maxima radio/engine sound

I have a '96 Maxima with a 5 speed transmission. Recently I had an aftermarket satellite/AM/FM radio fitted to replace the Bose unit. The new radio mated to the Bose hardware, so the speakers, power amp, etc. are all still the factory Bose elements. The problem is that I can hear the revs of the engine through then stereo speakers when I’m trying to listen to the radio. The louder I turn up the radio, the louder the sound of the whir of the engine in the speakers. If I turn the radio off, no more engine sounds. I’d appreciate any insights. In the old days, it seems like there were high capacity, or high resistance fuses one could use to address this kind of problem.

There could be several problems…First thing to check is the antenna connection. And check all grounds…

If there is no problem found with the antenna ground connections and radio grounding then make sure the alternator doesn’t have excessive DC ripple on the output due to bad diodes inside it.

There is no such thing as high resistance fuses. There are different types of noise suppression filters that can be installed depending on the type of noise being heard. If you are hearing a whine type of noise then the alternator is the source of the noise.

If there is no problem found with the antenna ground connections and radio grounding then make sure the alternator doesn’t have excessive DC ripple on the output due to bad diodes inside it.

The problem I have with that…is if it is the Alternator…then why didn’t he have this problem with the old radio…

No problem with old radio ,perhaps a difference in sesitivity or ability to block out the AC ripple in the DC supply. There may be a place where a filter can be placed in this system. What I wonder is why the OP is not going back to the installer. I had one ,lets say “eccentric” customer wrap his alternator in aluminum foil,he also convinced himself it worked.