Which direction do you flip the switch??!! This might be a stupid question, but my sun system 6 switchable ballast did not come with instructions... the advertisements only ever say "change from HPS to MH at the flip of a switch!" but the switch isn't marked "HPS" or "MH" it's marked "Model#M400" to the left and "Model#S400" to the right. is the M400 direction (left) for MH and the S400 (to the right) for HPS?
I would guess yes,the HPS needs a starter in the circuit which the "S" seems to designate and the 'M' would be for MH IMHO. Just my guesses mind you but if you put in the HPS and one position dont work the other will and answer your question but i say the #s400 position is for the HPS bulb. Do let us know.