Car Stereos: No power, amp shutdown, factory amps

Question
I have recently purchased a harness for a brand new aftermarket stereo for my 2003 Buick Lesabre. The harness is the GMRC-04. All I have done was connect the harness to the new stereo and pluged it in the dash. I checked the fused and the wiring and there is no power or sound to the console but the chimes work when I open the door. I eventually tried putting the original factory stereo back in checking the fuses again and the display for the radio and c.d.s work but no sound not even the chimes from the door being open. I haven't tried installing new speakers or an amp just the new stereo, is there any way you can help me I'd appreciate it a lot

Answer
Hi Bryan,

In most cases, I'd suspect a problem with a factory amplifier in a case like this; but all the information I can find on the LeSabre tells me that they don't come with factory amps.  All the speakers in the vehicle should be connected directly through the head unit through the contact plug.  Does your vehicle have rear door speakers, or just rear deck?  And is there a "Bose" or "Monsoon" logo?

When you're using the GMRC-04, the chimes come from the adapter module itself; but when you use the factory radio, the chimes are generated by the radio's internal amp and come from the driver's door speaker.  If the internal amp isn't working for some reason, that's why you wouldn't hear the chimes.  And the most likely cause for an internal amp shutdown is a problem with the speaker outputs.  I'm wondering if you may have some damaged contacts on the radio connector, so that two speaker contacts are touching; or maybe a speaker terminal is touching a ground terminal.  A shorted speaker output would shut down the head unit's internal amp, so you wouldn't get any sound.  This doesn't explain why the after-market deck won't power up, though.

Troubleshooting this problem would probably require some hands-on testing with a multimeter.  You can remove the stock deck, and inspect the contacts and ribbon cable closely for signs of damage or bent contacts.  If you have a multimeter handy, you can connect the GMRC-04 harness again, and test each of the speaker wires for continuity with the chassis ground wire, or with other speaker outputs.  You can also test the yellow and red wires from the GMRC-04 for voltage.

If you have access to a multimeter, and need some more detailed instructions on how to do your testing, let me know with a follow-up and I'll try to come up with a procedure for you.

Hope this helps!

Brian