Yes they do quite well in full sun, however they do like a little shade to. I have a good collection of Rhododendrons and they do very well in acid soil and i always feed them with sequenstrein of iron which they love.

The natural growing habitat of rhododendrons is semi shade, full sun can stress them. If you already have acidic soil there is no need to feed with sequestrene. The love a good mulch of humus rich compost or bark.

Do you know exactly which type of Rhododendron as its a very large genus. The dwarf, small leaved types with scented foliage grow above the tree line and prefer full sun as long as the ground is not too dry. Most others as said, (mostly larger leaved evergreen and deciduous types) prefer semi-shade.