I have a 2000 Toyota Sienna. At first I noticed that the dashboard light showing the left turn signal was on would light up when I put on the headlights. A few days later, I discovered that the left turn signal stops working when I apply the break. Also, when I’m using cruise control and use my left turn signal, the cruise control stops maintaining speed. Any idea whether this is a bulb, fuse or electrical problem?
You probably have a bad/loose ground at your left tail light assembly. If not that, then you have a few wires shorted together somewhere, maybe at one of the bulb sockets.
Thanks! That gives me somewhere to start.