Cadillac Repair: lights, turn signal switch, signel

Question
I have a 1996 deville when the head lights are off everything works fine but when I put the lights on the turn signel on the driver side won't work.  I checked the bulbs and they are ok.

would you know what the problem is.

Answer
Hi Ron, First thing I would do is put on the hazzard/4way lights and walk around the car and see what works and if all the bulbs blink with the same brightness. If a LH bulb was replaced then maybe a single element bulb was installed where a double element should be. You may want to remove all LH bulbs to check for this condition. Then put on the parking lights without the hazzards on and again see what looks differant. And finally park lights and hazzards at the same time. You could have a problem with the turn signal switch or a shorted out wire somewhere but a wrong bulb seems like the most likely cause. Bill