Radio works but there is no sound.

I installed a aftermarket head unit. Turned on for 5 seconds then went off, I have tried to put the old head unit back in, no power at all, I have checked the fuse, not blown. Any help would be great.… 

Had my Air con topped up, been working ok, now the light won't come off and recirculation light won't come on

Speakers aren't working when radio is on

Radio still works no sound from speakers. Just before it stopped working. Sound was cutting in and out. Then "pulse" sound came and went even when truck was off and key removed

The audio quit working. Radio comes on and shows that it's playing but no sound coming from speakers and no sound from blinkers