Works fine through 4 chnl. amp on radio until you switch to cd then rear speakers turn off

Did you make sure you have no shorted or grounded speakers or speaker wires? Make sure you don't have a bad speaker also. If everything checks out, you may have a bad internal output ic.

When your leasing to CD make sure that your EQ is still set up the same as when its in Tuner mode.

Hi there,
Well I found out on Pages 34 & 35 of the following Alpine manual:

http://vault.alpine-usa.com/products/documents/OM%20CDA-9856.PDF

---------------------
The Remote / Amplifier Turn On is a Blue/White wire.

if its working with the radio the fault must be the cd part of the radio hence take it back after testing different cds, home made cds may not be compitable with unit

Sounds like a lose wire in the harness either yellow, red or black. Pull radio and shake the wires around untill you find it or the face plate is lose.

check out www.installer.com
this site has your stereo's wire diagram.

The amp wires only go to the rear output (rca jacks on back of cd player)
It wont work right if it is connected to the front outputs on the back of cd player

i have alpine stereo's in all my vehicles and i have had this problem. if you run a 10-14 gauge constant wire from the stereo directly to the battery the stereo will not shut down in protection mode. it is not the cd it is the stereo going into protection mode because of lack of current not voltage. i hope this helps after i did this i could play the stereo as loud as it can go until my battery died

do you have another amp other than the one built into the head unit?

try checking all of the wiring and make sure the RCA cables are connected.

Radio is screwed.

But try these these steps:

Clean the eye of the head for reading CD. Must open up the radio.

IPod: check for good connections from Ipod to PCB.

The player has a built in safety device which only allows it to turn up so high. It help to avoid burning out your equip ment. Best way is to put sound on one device 3/4 ways up and then use the other device for adjusting the volume from there.

For sound in one channel; either there is a wire unplugged or not getting a good contact, or the player is set for mono instead of stereo