Cluster & Radio loosing power

[Mcwlandscaping]

In my 05 F350 w/ the 5.4 my gauges and radio keep loosing power at the same time. When the gauges loose power, the CEL remains lit so some things seem to still work but pretty much all the other lights go off with the gauges. I don't believe the gauges are on the delayed power relay as when I pull it only the radio turns off which makes me think it could be a ground that they may share? I have no idea exactly where they would be grounded to. Are the only grounds in the cab the ones on the dash support next to the steering column? I can hear what I believe is the delayed accessory relay powering off when the power (or ground) loss occurs. Can anyone give me some insight on this?

Also, in a probably unrelated case, I'm also getting a P0446 code. Where should I begin checking for causes of this. I know it has to do with the evap emission system vent control circuit but I'm not sure which evap system component is the valve in question.

Thanks guys!

[96Wronco]

Evap I would make sure your gas cap is sealed and such because usually that can set a code.

I'm not so sure about an '05 but I think there may be some grounds behind the kick panels on either side of the truck. Not sure if they will be for the gauges or radio, but they are worth checking out.

Have you ever unplugged anything under the dash or in the engine bay?