The next step is real easy. You just remove the supplied holder nut on the switch and put the switch through the hole you drilled and put the nut back on the switch securing it to the ballast housing. Reassemble the balast and you now have a switchable HPS/MH ballast. I usually test it to find out which side is the HPS and mark it with a sharpie. Test with the HPS bulb as it will not fire if the ignitor isn't in the circuit. Voila, you are done
djsethall Reviewed by djsethall on . Converting a standard HPS to a MH/HPS Switchable for less than $8.00 Ok if you are not comfortable working with electricity and do not know how to make safe High voltage connections, DO NOT ATTEMPT Now the discalimer is out of the way. OK, you start with a standard HPS ballast and crack it open. Remember that most manufacturers will void the warranty if the ballasts seals are broken. With that said, lets begin the surgery. After the ballast is cracked open you need to locate the ignitor (generally next to the capacitor but smaller) and trace the wires Rating: 5