2 possible issues.
1st You have a factory amp on the vehicle. You need to turn it on with the new radio remote power wire on your new radio. This wire is blue with a white trace. Hook this to the 2 blues on the BT ISO DIN and this should turn on the factory amp
2nd
You have a ground speakers lead. Test all the speakers for short to ground. Do this with a continunity tester or ohm meter. If any wire of any speaker is grounded the radio will shut off the audio.
Hope this helps