I just recently replaced all of the factory speakers in my 2004 GMC Sierra Crew Cab with Infinity Kappa 6.5s. I also installed a Kenwood Kac-8405 720-Watt 4/3/2-Channel Amplifier to power the speakers. I have the power wire run down the driver side of the truck and the RCAs run down the passenger side. The power wire is 4 gauge and runs to a distribution block by the amp where it tapers down to an 8 gauge wire connected to the amp. I kept the factory head unit and used a PAC AOEMGM24 Add An Amp Interface to run the RCAs. The previous owner of the truck had an iSimple PXAMG Gateway installed to provide an iPod input. So, the iSimple unit and the PAC Add Amp interface are both plugged into the factory harness. Everything is working great and the sound overall is fantastic. But, I've noticed that when I turn the volume up to a moderate level and pause the music, I can hear a faint crackle out of all of the speakers. I've disconnected and reconnected all of the speaker wires and RCAs one by one to see if the noise stopped, but no luck. The ground wire is solid. I've narrowed it down and realized that the crackle seems to only be present when using the iPod input. I can't hear it on the radio or when playing a cd. So, I'm a little at a loss. Do you think that the iSimple unit has an issue? Would an inline noise filter help? Any suggestions anyone? I appreciate your thoughts...
Can you connect via bluetooth? Anyways you can get an aftermarket HU for the same price of that iSimple and a very good HU full of features for less than $200.
The iSimple that was installed is not bluetooth. I realize I could replace the head unit but I like the factory look and don't want to. I also don't want to lose the steering wheel controls and other extras that are part of the factory HU. I didn't install the iSimple. It was already in the truck when I bought it.
Maybe the cable or the terminal to either the iPod or the iSimple have an issue, you could try to set an analog connection from the headphones jack to the one on the iSimple.
Anyways there could always be an issue with either the iPod or iSimple even a compatibility issue between them.
You should also check that your electrical system voltage is above 13V when playing loud, low voltage can upset some devices.
If tech support of the iSimple can't solve the problem you may have to try another device. Also test the iPod elsewhere, there are many high end alternatives to that iSimple like the bit one, ms-8 RF 3sixty.
Also for some cars there are ways to avoid losing your wheel controls that be some devices or even moving the stock HU to the trunk believe it or not.