I have a 2005 gmc sierra crew cab, and the Bose system won't work right to save my life. I have an aftermarket head unit, but the volume always had to be maxed out to hear the sound. I took it to car toys, and he said it may be on the low setting. So he charged me 100$ to "fix" it and now it's loud, however the RF door speaker doesn't work, and the LF Door is crackly and poppy. Any help would be greatly appreciated I'm really frustrated now.

SOURCE: 02 GMC Sierra Denali Radio

if they do not help you here is a place that sell only GM parts it is a place call schram auto& truck parts the # is 1-800-292-1032 and they can even sell you the right one for your truck if needed.

SOURCE: 2005 GMC Sierra 1500 crew cab - speedometer not working

This is a well known issue with model years 2003 thru 2005. There is a chance GM will replace it under recall... Call the Chevy Customer Assistance Center 1-800-630-2438 to find out.

If not and you want it fixed, try Southern Electronics at http://www.instrumentclusters.com/.

SOURCE: How do I remove the door panels on my 2005 GMC

Try this website and download a FREE service manual that will have photos of what to remove to change your speakers

http://ezinearticles.com/?Find-the-Free-Auto-Repair-Manual-You-Need-Online&id=92717

SOURCE: The stereo in my 2008 Silverado has very low

If it has a premium sound system some of them have a small amplifier for the over all system and the rear out put may have lost signal out put power.If it does not have an amplifier then I would replace the head unit(deck)with a brand that you like so you have total control,and no that does not sound right.Hope this helps