Fog Light Switch problems of the 2004 Toyota Prius

We've noticed this problem only a few times in the car since we've owned it. That's been about 3 years. We seldom drive at night but whenever we have it's always been an issue. Usually just the left goes out and resetting the lights brought it back on. This past week the same thing started to happen and resetting it worked a few times but then both headlights went out and resetting the switch did nothing. Thankfully dawn was on the way and with the fog lights on we just kept going. Once I felt comfortable turning the lights off completely and after waiting 3-5 minutes with the switch off I tried the lights and they came back on. There is definitely a problem with something; maybe an overheat issue with the bulbs, wiring or control box. This is a huge deal. If we'd been driving into the darkness instead of dawn could easily have had an accident.

While driving at night, my headlights will turn off randomly. Sometimes, it is just one but often it is both. If I turn the headlights switch to off and back to on, sometimes one or both lights will turn back on. More recently, this trick hasn't been working as well and I have to drive just using my fog lights. It seems to be something with the computer that controls the headlights. If it was the bulb it would always be out. If it were the wiring, simply flipping the switch on/off wouldn't suddenly get the wiring to connect again.

Problem started with the right headlight turning off intermittently. I reported the problem to the local dealership on 8/27/2013 when the vehicle was serviced. The dealership indicated that they could not find a problem because the problem could not be duplicated. Then the same thing started happening with the left headlight. I can correct the problem by turning off & then back on the light switch but this correction does not last long and the problem recurs. I have resorted to driving with my fog lights also turned on in order to provide some semblance of light. It is difficult and dangerous to drive like this in the long alaskan winters with so much ice and snow on the roadways. I can also make this problem occur when warming up my car in the driveway.

2004 Prius at 146k miles with original headlights. Drivers side headlight turns orange and goes out after 2 minutes. Passenger side light goes out randomly and takes out fog lights at the same time. A complete failure of forward facing lighting including fog lamps should not happen if a headlight goes out. Turning the lights off-and-on brings them back for an unspecified amount of time until complete failure once again.

Random headlight failure. When fog lights are not on total failure of headlights has occurred. Right, left or both headlights will go out with no correlation to weather, speed, temperature, location of lamp or time of day. Quickly turning the light switch off then on will reilluminate both lamps. The lamps may go out again, stay lit, the same lamp will go out or the previously lit lamp may fail and the previously failed lamp may light. There is a reduced interval between failures . Lightbulb replacement has been suggested but this has not solved the problem for similar complaints.