47 CJ2a intake manifold heater

[SteveBonny]

I'm wondering if the intake manifold heater is assembled correctly on my 47 CJ2a. The lever is always in the upmost position whether the engine is hot or cold so it is apparently doing nothing. Is there an easy way to know if it is assembled correctly without removing the manifold?
Should this contraption be active in normal summer weather (Iowa) with a cold engine or would it just be active in winter weather?
Thanks for any advice!