noises with new head unit

[army26m]

old z919 stopped playing cd's. so i had a alpine 9856 installed. from the start, radio stations that i know to have strong signals now have static on them. today i heard the electric mirrors threw the rear speakers. took it back to the shop, they thought it was a faulty head unit. replaced with another one, problem still there. cd's play clear but hear mirror noise then too. the shop is saying its a bad ground in mirrors, but not with their installation. they want me to come back so they can tear the door panel off to check the mirrors grounding. if it was a ground problem wouldnt it affect more then just a weak radio signal and mirror noises? i dont hear any motor noises or hums. any thoughts?

i didnt have any problems with old unit other then didnt cd's

 

[FoxPro5]

No ******* way it's the mirrors man. Who installed this?? You have a ground loop.

 

[1sty]

My integra had this issue way back when. wish I could remeber what caused it.

my only thoughts if you only have an aftermarket radio and nothing else is that the accessory power wire or the ground at the radio isnt actualy conencted in the harness. I would tap a new power, accessory, and ground lead to be sure they are clean.

As a last alternative, see if anyone local can lend you a factory mazda radio (not kenwood) and see if it still has the problem.