Question
QUESTION: Hi Jim,

My RD 900 controllers works for stations 3-9 but misses 1 and 2. Transformer voltage is 24 VAC, 0 DC, as it should. Stations 1 and 2 when one read 7-8 V AC and 14 V DC. What could be wrong? Thanks

ANSWER: Hey Omida, it could be a short in a wire, a solenoid, or the circuit board. First take off the wire on station #1, and then check your voltage, if you are getting 24 volts (or close to it), then the problem is either in the wire running to the valve, or the solenoid is shorting out. If you are not getting the proper voltage with the wire disconnected, then it is in the circuit board, and this board needs to be replaced. Good luck and have a great day.

---------- FOLLOW-UP ----------

QUESTION: Thanks Jim. The voltage read across stations 1 and 2 are about 7-8 V Ac plus a large DC (14V!) measured at both controller and also at the point of connection to the valves (without  solenoid disconnected). The fact that I have a DC voltage tells me that the AC switch (is it a Triac?) is fried.

Also, I noticed that the installer didn't connect the ground pin to the house ground, against the recommendation in the manual. Could this damage  circuit during disturbances such as lightening? Thanks again

Answer
Hey Omida, yes you are correct, you might be able to find a local irrigation supply store that could repair it for you before you replace it. I would also recommend connecting the ground wire if it is not already installed. Good luck and have a great day.