Chev Lumina with factory Delco head unit, with Speed Compensated Volume (SCV). This unit started to pop the speakers and volume would drop when the gas pedal was depressed. The conclusion was that the SCV circuit in the head unit was failing.

I replaced the head unit with a Sony CDX-GT410U. I am not using an AMP or subwoofer, only the factory 4 speakers. I purchased a conversion harness to make the install easier.

When parked, the stereo works perfectly (as did the original factory head unit).

However, even the new head unit pops on the speakers a few times when you first accelerate the car, and eventually the error code FAILURE is displayed on the screen. The radio does continue to operate normally however, except for the few speaker pops during initial acceleration.

It looks like my original head unit was not the problem after all?

Can someone suggest some things to check when starting to troubleshoot this?

Thanks in advance.

 

sounds like a short in either the ground or the power wire... have you checked the battery terminals??? its definatly a wire shorting out.

 

that sounds like you have a factory amplified system
the issue may very well be in there

 

I'm not sure if it matters or not, but some more testing revealed that:

Voltage on + and switched + wires is 12.7.

Also, with the new head unit, the speaker pops I described are not really pops, they are actually more of a buzz sound, but the pitch of the buzz seems constant, it doesn't change with the RPM of the car.

I rewired the ground from its first position (attached to the ground wire of harness kit) and tried grounding the head unit directly to the metal frame under the steering column. Changing the grounding location did not make any difference to the buzz sound.

 

that voltage is fine...... do you have a factory amplified system, the other thing to check is the rear speakers and make sure the tinsel leads are still in tact

 

Thanks for your reply, and please forgive my ignorance. How would I find out if I have a factory amplified system? The head unit I took out was the standard factory Delco AM/FM/Cass with a product ID of FM20EV. It looks like this:

http://cgi.ebay.com/ebaymotors/1998-99-2000-Chevy-Malibu-AM-FM-Cass-OEM-Delco-Radio_W0QQcmdZViewItemQQcategoryZ38639QQihZ006QQit emZ160098075949

I googled tinsel leads to see what they were. I will check the rear speakers tomorrow to see if anything looks out of whack. I might disconnect the rear speakers and test the system again to see if the problem only happens when the rear speakers are connected.

It is interesting that you question the rear speakers. It was hard to tell but I wondered if the buzz sounds came only from the rear speakers.... I thought maybe it did, but it was hard to tell.

Also of note... the error code FAILURE displayed by the new head unit is described in the manual as: "The connection of speakers/amplifiers is incorrect."

Thanks for your help.

 

I believe I have solved my problem. Many thanks for your help, you were exactly correct!!

This morning I checked the rear speakers and the plug for the left rear speaker had become loose from where its fixed to the speaker frame (probably the result of being knocked when loading the trunk).

As a result, the tinsel leads were out of position and were shorted against the metal speaker frame.

I have reseated the speaker plug properly on the speaker frame which realigned the tinsel leads, and everything is working well now!

Thanks again!!

 

no problem glad i could help have a great day

 

Holy crap, Garrett, you got something right!