I have a 1989 nissan maxima se, with the Bose sound system.I have a problem with the stereo. When i turn the stereo on then rear speakers start to make a weeeeee ing noise. I dont know if i should change the whole system or just the rear speakers or a new deck. I changed the deck to a different one. Any help would be appreciated.

 

Possibly Alt and/or a grounding problem.

Disconnect alternator to test. If problem vanishes, check page 23, link below

If no change, start work on groundings, connectors. Re-route speaker wires. See link below, pages 10 &14.