Possible Cause: Possible short in wiring
Action: Check wiring to be sure there are no shorts . Possible incorrect fuse rating (15amp required for radio), DO NOT Increase the size of a factory installed fuse, this may cause a fire, ensure that the wiring is of the correct gauge, if necessary, run a replacement feed directly from the battery with the correct rating of fuse and gauge of wire.
Possible Cause: Vehicle is positive grounding or battery is in backwards (wrong polarity)
Action: Check vehicle for correct negative grounding system or verify battery is installed correctly. (Retrosound radios will only work on a NEGATIVE ground/earth system