battery drain

We got an 02 gmc denali at the shop that we installed an eclipse nav headunit a while ago, customer is complaining that the battery dies within 2 days of the car sitting, we have had the car here for about 2 weeks now and sure enough every 2 days we have to charge the battery, i disconnected the battery and put my amp meter inline and i got a .02 amp draw we i dont think it should be enough to kill the battery in 2 days, any help?

thank, steve

Since you have the truck in shop...have you tried to disconnect what you installes to see if thats in fact the issue?? thats where I would start and then go over my install step by step.

good luck