It can, but very informally, almost slang. Normally you'd say "exciter" or something like that.
As for "start" I think it's a very poor translation for "allumer". The only situation I can think of where it'd mean something like that would be the idiom "allumer la mèche" (lighting the fuse, as in for an explosive) which means that you're "sparking" something off (like a protest for instance).
Allumer can mean "to light" in the context of a flame, i.e., bougie (candle), poêle (stove), briquet (lighter), gaz (gas), "to strike" (a match), "to start" (a fire). Generally, it means to turn on/put on/switch on some device (a light, an appliance, the electricity). It can also mean to "stir" or "arouse" a person, i.e., to turn them on. http://www.oxforddictionaries.com/translate/french-english/allumer
That would apparently be something like "who is he flirting with":
It doesn't seem out of the question to me.
If the context (that you are thinking of, because there is no context in the sentence itself) results in a translation which is "off", it would only be because you have chosen a translation word that doesn't fit the scenario you imagine. If you envision pushing a switch to enable the lights, then we would say 1) turn on, 2) switch on, or 3) put on... a light, a lamp, an appliance, a motor, a generator, etc. But If you are "lighting" something, the referent would be a candle, a match, a (gas) stove, a pilot light, a lighter, etc. Rather, "to light the light" is the stuff of poetry and romantic lyrics (Bye Bye Blackbird).
In general I support adding all reasonable possibilities, but the difficulty here is that the definition you're referring to seems at present to appear only in Wiktionary, which makes it suspect, and probably wrong.
It's possibly a misunderstanding based on the adjective "alight", which means "on fire" or "lit/lighted (up)".
It looks like the proper archaic form for "to light (sth. up)" might even be "to alighten", not "to alight".
So do I, and I refer to it often, but I've come upon a wrong entry or two (for example feminine and plural variations for an invariable French adjective, apparently added by a bot) – or at least entries that I couldn't find support for elsewhere that struck me as unreliable – but it's been rare.
Per robertcollin, you could say "qu'allume-t-il"; I don't see "quoi allume-t-il" as an option. As for "quoi il allume", I think that might be possible, but if so, very colloquial and not as common as "il allume quoi". I defer, of course, to native speakers or anyone more knowledgeable.
The error was in the conjugation of the English. In the form of a question, you may say "What does he turn on?" or "What is he turning on?" Although it is possible to put "what" at the end of the sentence in English, it is just a bit awkward and it would also require "He turns on what" (not "he turn on what"). For more possibilities to understand the application of the verb "allumer", please read the comments above.
"illume" is not a word, "illuminer" is to illuminate, maybe that's what you're thinking about?
There's also "éclairer" which is to shed light on something. "Les phares éclairent la route" ("the headlights light/shed light on the road").
That being said "allumer" can be used for "to light" as well, "allume le feu" (light the fire), "allume la torche" (light the torch). It's also very common to say "allume la lumière" even though it's a bit redundant (turn on the light, literally "light the light"). But it's always is the sense of changing the state of something, unlike éclairer which means using an external source to bring light to something.
So "allumer la bougie" is "to light a candle" but "éclairer la bougie" is "to shine light on a candle" (using a flashlight or something).
I am a native English speaker. I am questioning the difference between my answer which was "incorrect" and duo's answer. I wrote "what is he turning on". Why is the word "does" (present tense for doing it..) correct? Does it have something to do with the verb "allume" that escapes my imagination?
Your answer should have been accepted, and I'm surprised that at this point it wouldn't have been, but the "does" version is okay too.
What is he turning on (right now)? What does he turn on (every time he gets in his car)? Both senses are legitimate interpretations of the French.
I would agree that this is a dodgy translation and it would be much better (and better English) to say 'switch on' rather than 'turn on' in this context to avoid ambiguity. Can't report that though, because as so often in the French tree there is no option on the reporting buttons for the English not being correct......
There's nothing to report. The expression has the two different meanings in both languages, so the same ambiguity technically exists in both, which is a good feature of a translation. However, really only one of the possible interpretations is reasonable in either language anyway.
Perhaps you feel differently about it as a British English speaker (I'm speculating), but for North Americans "turn on" is more common than "switch on", and there's really no issue here for the average person.