It. Beeps 5 times when turned on for a series of 5 and then every 20 minutes repeat itself

Hello, sounds like possibly a case of the air bag / restraint system warning light being burned out -- and the system basically telling you that there isn't a problem -- or maybe that there is, depending on beeps. If I'm remembering correctly, 5 beeps is a pass code. Check to see if the light for the restraint system "proves out" with the key in the "on" position initially. It should stay on for 5-10 seconds then go off. If it does not go on at all, then this is confirmation of your concern.