Well, we know it's not a head unit issue more so it's probably a wiring issue.
I would say that you have either interference from another source tying into the RCA patch cords OR your not measuring the RCA's right or the amp is blown (not likely).
I've run into this problem before and what the problem was the ground to the head unit was not strong. Make sure all the fuses in the wiring harness are good and ALL connections are strong.
I would recheck your ground and maybe putting your ground in a different spot. Check it with the DMM in the ohm position and make sure that there is very little to no resistance in the connections especially the ground.
Let us know how this turns out... I'm interested in the result
I would think that is the problem. Always make and secure a soild ground. //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif
Generally, if you are looking to measure resistance you would stick the probe in the front/beginning of the wire and probe at the end/harness of the wire for resistance. The least amount the better when measuring resistance in wires.
Example: Your ground..
Measure resistance beginning at the harness plug (black wire) to where you have the ground wire bolted down. If you measure 0 resistance then your good, but if you notice no change in the reading then your open and need to make the correction.
To test your ground:
Find a constant 12v source and plug the red end of your DMM into it measuring DC Voltage.. DC Voltage, not AC. Then stick the black end of your DMM to where you bolted your ground and see if you measure 12v on that end.. if not, there is your problem.
ok so i tried to take all the guess work out of it....brought the deck inside hooked it up to a 12v computer power supply and STILL only get .1V everytime the track plays