Turn the ignition off then on and see if everything starts working again. I had a bad ignition switch in my '00 do weird things.
Make sure your battery connections are clean and tight also. That's step one.

 

If it is JUST the radio and blower going out, you can check the wiring harness going to the back of the control cluster. When I got my 02 Sable, I installed an aftermarket stereo and in the process learned that the previous owner also apparently had an aftermarket stereo and had put the original back in for the sale. His wiring job was... lacking. If when the blower is going you hear a whine in the speakers, then it is likely a ground issue. The stereo and blower should not be on the same ground, but sometimes it happens.

But as Repairman said, it does sound like you might have a bad connection to your battery. Wiring under the dash shouldn't affect your RPM's.

 

Thank you for the replys, when the blower motor / radio cut out it's only for a second, two max. In the time it would take to turn it off and restart the car it would already have come back on. All the battery leads are clean and tight.

When checking today I noticed the a/c compressor also cuts out when this happens. I also noticed when on, the compressor clutch is a little noisy, like it's scrapping internally. So I disconnected the lead to the compressor, and the issue stopped. I'm wondering if it's possible that the a/c clutch has a short and that is the cause.

 

For good measure, take off your engine to firewall ground strap and clean
its connections and put it back on. clean your battery cable connections.
clean any ground lugs on the fenders and such

The AC noise is probably the pulley bearing going bad. Could be the pump too.

 

Worth checking the condition of the ICP fuses (20,24,32) and contacts for corrosion or looseness

 

Thanks for the advice, all battery leads are clean and corrosion free. I'll check the ground strap, and fuses.