installed a new jvc 200 w kd-g200 radio in a 1992 300e a benz

radio is connected like so :


radio reciever inside wiring of car
yellow ( 12v) ------ red and white ( constant 12v)

red ( accessory ) -------- black and yellow wire

black ground --------- brown

antenna is universal black ---------- red and white also constant 12 v


only dash and door speakers connected not rear( blown ) so i have all 8 wires from car hooked up to the four wires for front speakers .


speakers are on when the car is acc position but when car is running the speakers shut off ....

occasionaly when the car is running and you hit a bump the speakers will then come on .

what is wrong plaese help