onstar in a 02 monte

Has anyone had any trouble with Onstar after doing work on a GM car? Today I added an Equalizer in a Monte Carlo which still has the stock headunit in but has had an amp added for the front speakers and the subwoofer.

I didn't even remove the headunit from the dash all the work I did was in the trunk since this is where the Line output convertor was put by the previous installer. I simply ran rca's from the convertor to the console and back.

After the work was done the customer called back and said his onstar is not working and he has lost the door chime. Not sure what I could have done to cause this but the car comes back next week for me to look at.