As said check for fire at the downstream (brown wire) end of the ballast in ign1 (run) to see if it's open & if good work back toward the ign sw (start w the bulkhead). I just checked a bunch today & got 1.3-1.6 ohms on a handful of 2 prong ballasts and 1.6/6 on a 4 prong unit & w it in parallel reduced it to 1.1 which w work excellent. EDIT if you want to mix/match/experiment you can wire in the 4 prong connector (2 dual connectors) & the width is just right so you can use 2 single ballasts side by side. Wire em in parallel & ohm it