hi

i just had my z1 installed and when i use onstar it has static. any help on this

What kinda car?

Make sure you have used a new ground, not the ground that was used for the factory radio. In fact, to be safe, find a location on the steel cross member behind the radio, ground the AVIC to that point and if you want to make it better, run another ground from that location to the negative battery cable.

Factory radio grounds are not good for many aftermarket radios due to other components using the same ground location at a ground splice. GM and other manufactures spend thousands in researching and testing what is a good ground for the components. Adding an aftermarket radio or any electronic item, may cause static or whine.

.....GM and other manufactures spend thousands in researching and testing what is a good ground for the components....

You'd think that right? Not really I've seen many times where FACTORY equipment or systems failed due to a faulty ground.