What the heck is going on with my car?

I have a 2003 Toyota Camry. After driving it around for a day (I have to admit, I was driving the car pretty hard that day), I got home and the headlights didn’t turn on and the engine light was on. I turned the car on and then off and the lights worked fine but the engine light was still on.

I then took it to the dealer where they said that the engine light was on because the thermostat was broken and everything needed to be flushed. So I ponyed up the money but when I got the car home, the lights didn’t work again. I told this to the dealer who said it was a completely unrelated problem to the engine light.

After taking it back in, they said the only problem was that one of the bulbs were burnt out and since the lights were on the same circuit, it caused both lights to go out. They only replaced one lightbulb (I’m not sure which one)

The lights were working fine for a couple of days and now one of the headlights doesn’t work again.

My question is what the heck is going on? Is it really all just a big coincidence. Could there have been some sort of powersurge or something related to the engine light coming on that caused my lights to burn out? Why was I able to turn the car on and off the one time and have the lights come back on? Does the mechanic at the dealer really have any idea what’s going on? I’m not much of a car person so any insight would be appreciated.

The light trouble has no relation to the headlight problem. The ECU turns on the CEL light when something related to the emissions of the car is detected to have a problem. The headlight trouble may be due to a faulty relay, switch, or connection in the light circuit. Testing for power at key points while the trouble is occuring would be the best way to find the trouble.