For a little over a week my driver side turn signal and brake light has been out on my 2007 Dakota and I’m trying to figure out exactly why, or what part I need to replace. The bulb itself is fine, I checked this first, and later noticed that the nigh time running light still works, so the dim filament is getting power and ground, but the bright filament isn’t. I checked the voltage at the light and got less than 1 volt or none at all. The indicator clicks very quickly when I engage the left hand turn signal, as if it were open, and normally on the right. Does this indicate that the multifunction switch is dead, or should I look elsewhere before replacing this part?

 

Look elsewhere.... Find where you are losing voltage.