Hey guys, I have been having this issue for some time, but it never was as bad as it has gotten recently.

Periodically while driving the Radio will turn off like I turned the key off. When this happens I figured out that the windows will stop working and the radar detector will cut off as well. The door locks and mirrors will continue to work and all other acc. seem to work. It is very random when it does this, sometimes lasting only a second or two, other times lasting 5 minutes or more. Sometimes I will get frustrated and hit the dash and it will come back on, other times it does nothing so I don't fully think me hitting the dash helps, but that it's a coincidence it happens to come back on when I hit it. This morning it did it 6 times on my 20 minute drive to work each time lasting about 4 seconds. Anyone have an idea where to start to track this down? I have changed the fuse for the radio (window is a different fuse then I keep so I haven't tried that yet), I have checked the wiring to the radio as best I could and it has been changed out twice and new harnesses added on.

Mods and points that might help:
It just started one day a year or two ago, nothing changed (no new mods) before it started, just happened one day. I've been too lazy to track it down until recently.

It has done this through three different radio installs. So I don't think it's the wiring from the radio grounding something out.

I have a Viper alarm that was swapped out about 3 years ago from an older one that was installed on the car. Could this be doing it? This past weekend the alarm stopped unlocking my doors so I dropped the rats nest of wires to check it out and didn't see anything out of the ordinary as far as exposed wires (The door not unlocking is a relay going out).

The Radar detector is wired into the radio ignition fuse and it cuts off as well when this happens. The Remote wire for the amp's are also wired into the radio ignition fuse, but I am not sure if they cut off, I assume they do. Radio fuse has been changed and is very tight, so I don't think it could be that and if it is it shouldn't bother the windows. I did notice that the window fuse is right over the radio so I don't know if that helps.

Any idea where to go from here to figure this out is greatly appreciated.

 

I'm not going to read all of that so excuse any ignorance in my response:

check for loose power/ground connections to the BCM, which is responsible for RAP power -- replacing them isn't cheap or simple so look it over real good before considering the replacement procedure

 

Great Idea, I will check that out.

 

I have the exact same issue with my radio/window. What's weird is when they come back on that all the presets and time are still there. So they are not losing all power. On mine, it usually comes back on if I hit the top of the dash. Have you been able to find the problem? I would really like to figure out this issue. It's getting worse and it's really starting to irritate me.

 

Well it's just as you turned your car off and left it -- except the BCM (for whatever reason) is behaving like that while you're in the car. The HU still has constant voltage from the battery for memory.

 

Exactly. Any idea on how to fix it.

 

I did some searching for a lose ground, but I have a remote start alarm under the kick panel so it's a rats nest of wires and you can't even see the BCM without a lot of digging, much less track down a faulty wire coming from it. I plan to replace the BCM when I get a chance and see if that fixes it. I did find hitting the bottom side of the dash seemed to help the most, but usually it would just turn back off.

 

What and where is the BCM?

 

The BCM is the Body Control Module. You can get it on GM direct for around $100. If you drop the kick panel under the steering wheel, it is on the left hand side toward the back and has a lot of wires coming out of it.