My h2 came with a pioneer radio installed by the prior owner.Does anyone know how to turn up the volume on the onstar? I can barely hear it underway..

 

should have a little black box in there for the wire harness with an adjustment spot on the side to turn up onstar and audible door chimes.

 

Thanks I will try it..

 

Finally figured it out after online research..There is a black and yellow wire on the wire harness connected to the radio.to increase volume touch the wire to ground. There are 4 levels.I am going to install an intermittent switch so I can adjust while driving.