I was metering 0 to -.01V on the mute line against ground no matter what. So i figured it was just going from 0V to an open circuit. And yes i had the ignition on or else the wireless phone kit wouldn't work at all =].

I tried for a good 30 minutes to get a repeatable behavior but just when i thought i did it would do something different. I know the right wires are connected, i've checked that 5 times. I know the phone works, and i know that at times the empeg does see the mute action because it will pause, just not reliably and not when it's supposed to. Sometimes the empeg would start up with the phone icon on, and the music playing. Then i'd make a call, and the phone icon would disappear, but the music wouldn't pause. Then when i'd hang up, it would pause. Then i'd shut the car off, pull the empeg, reinsert, turn ignition, and the empeg wouldn't have the phone icon up or react at all to a phone call.

Two things i can think of that i need to rule out... the mute connection on the sled harness might be dodgey, and the resistor itself. I didn't think to check it's value with a MM... so it may have been faulty though that's probably unlikely. It's now sitting on the side of the street somewhere as a lead broke as i was removing it, so I'll have to get another anyway.