How can i find out what is wrong?

Left indercator stays on constant, along with reverse lights all on the passenger side. When breaking reverse lights work as the break light.
Comes and goes when it likes for example; everything is normal in the van but when i indercate left the reverse lights flash this is when my headlights arnt on (daytime).
When foot on break, i can take the key out of the ignition and the engine still runs??

Has anyone ever came across this problem before?