Two problems related to tail light switch have been reported for the 2004 Toyota Prius. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Prius based on all problems reported for the 2004 Prius.
Our 2004 Prius has intermittent problems with headlights and tail lights failing. One of both headlights will all of a sudden go out. Turning them off and on usually causes them to come back on. My son was driving on a curvy, dark forested road when both lights went out. Could not see a thing. This is an extremely dangerous situation. We have also replaced tail light bulbs. They work, then fail again quickly.
The passenger headlight and taillight stopped working. We replaced the tail light bulb only for it to stop working two days later. We replaced the tail light bulb once a week for a month, and for now it continues to work. The headlight, however, continued not working for about two weeks, then began working again only for the driver side headlight to stop working. After turning the headlight switch off then back on both headlights began working. However, after 10 minutes both went out again. Ever since then, it is always a guess as to which headlight, if any, will work at dusk. Sometimes they will both work for about a week before quitting. I was given an odi# of 10453541.