Jandy transformer voltages seem odd


Jul 21, 2014
My Jandy Aqualink RS control board does not power up, i.e. no visible lights and no command functions. I reset the board, tripped the breakers to let the system rest, removed and replaced the lithium coin battery, all to no avail. I checked the secondary on the center-tapped transformer and the two hot wires (yellow) together read around 25vac as expected. But when I test each leg separately, one leg shows 11vac while the other leg shows 14vac which of course equals the total voltage.

Before I send this board out for repair, does this unequal voltage seem suspect? Thanks to all.



Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

In the past 55 years of working on this stuff, I have seen less than 5 bad power transformers. And... everyone of them was installed wrong and blew up when initially powered on. About the only way to hurt one of them is to connect a 120 volt transformer to 240 volts...


Jim R.