So i replaced my headunit for one with iphone compatability. I took the boat out today and realized that with the iphone hooked up through usb and playing it works great. But once i crank up the volume headunit shuts off. The ground for the headunit is running straight to the battery. I am wondering if the phone is drawing an extra amount of power and what i can do to fix this. Thanks in advance.

I might suggest that you just take it to a shop if you don't have the basic diagnostic skills. <BR> <BR>I highly doubt the iphone draw had anything to do with it. More likely is that your signal is stronger and it exposed a weak link that already existed before.

what might that weak link be?