White- Westinghouse fan oven model 200100

I have an above oven, the fan will not come on or the indicator light come on. the function selector has a couple of times in the past seemed stiff and the light not come on, then by switching the selector the light has come on. Now though there is nothing happening when turning the selector except for a brief dull flash from the indicator light. The oven up until now has been functioning ok, although we could never use the oven conventionally. Has anyone any ideas, I would be grateful to receive them