2003 yukon wbose hu cuts off

All right you guys I need some pro help. I had a Pioneer AVH-X3500BHS installed in my 2003 Yuke with Bose system and left everything else stock ...speakers. The HU seems to work fine, but every once in a while it just cuts off. The power goes out, the HU turns completely off then back on in about three seconds and resumes playing. The shop that installed it can't figure it out. they've swithed out the HU and some Bose module, but that didn't work. I dont want to have it uninstalled and  my original HU put back in, but at this point that looks like my only option. Help me/them out here guys. Thanks.

does just the sound go out or the radio itself seems to lose power and then turn back on? if the radio loses power then it can only be a loose connection somewhere, possibly a loose ground. also depending on which kind of adapter was used to interface with the bose system it could be just a case of cheap equipment

Have them connect the Deck's yellow wire to the other end of the bose adapter. Especially if they are using an OS-2C-BOSE piece. In other words do not pull the current for the head unit through the piece. Catch the wire between the factory plug and the box. That unit will not provide enough current to run the display on a video screen.

Thanks guys, I'll have them look at your replies to see if it helps, then post a follow up. For further clarification...the HU turns completely off; no indication of power, nothing is illuminated on it, and no sound, then it turns back on and resumes playing. Also, if it was a loose wire, I think they would have nailed that down considering they've removed the HU no less than 4 times between replacing it and troubleshooting it. But you never know. Thanks again

dont assume the installer knows anything, just because you can install something doesnt mean you have enough experience to identify the little random problems like yours that can happen. the problem could be a lack of power like IAAI said above, it could be a loose pin inside the plug, a pinched wire somewhere, ground loose or not in a good spot. or maybe there are a few other accessories tapped off of the same power wire and all of those devices are combining to draw more power than the wire can handle, in which case the first thing that turns off will be the device that needs the most power which is probably your radio.