There are two motors in the RC Series Rainbird indoor and outdoor Controllers. There is a timing motor that allows the controller to keep time and is also responsible for slowly moving the large dial slowly through the watering stations when the sprinklers are in a watering cycle. This timing motor can easily be differentiated from the other motor, which is the Advance Motor, because the Timing Motor has a much shorter shaft. The Advance Motor is the one that clicks rapidly as it advances the large wheel between watering stations.

Two easily noticed symptoms of a defective Timing Motor is that your controller no longer keeps track of time. Secondly, if you turn a watering station on manually, the large dial will not move through the watering station and if left alone, would water that same watering station indefinitely. 

If you can operate your watering stations by turning your large dial manually to each station, it proves your transformer is not the problem. Next, set your hour dial on the correct time and check back in an hour, if it is still sitting on the same time you set it on, hasn't moved, the timing motor is probably a problem.

Also keep in mind the plastic gears inside the controller mechanism frequently develop cracks near the hubs of those gears on older controllers. So you may not cure the problem by installing a new motor. We recommend checking for cracks before purchasing a motor. If you find cracks in some of the gear hubs and the controller doesn't keep track of time, you are advised to ship the unit to us for diagnosis and 24 hour repair - in one day, out the next. Bench check of $32.50 includes all repair labor and testing. Cracks are visible in bright light and usually occur at the point where the molded plastic of the gear meets the spline of the aluminum shaft.

If you decide to do the repair, motors are easily installed , as they are mounted with only two easily accessible screws and are connected with two wires that cannot be mixed up, either wire connected to either point will work. But don't forget which two wiring points connect to your motor wires. One of the two yellow wires exiting the motor connects with several other wires at a wire nut. The other yellow wire is connected (soldered) to a fuse container or circuit breaker assembly.

The easiest way to install a new motor is to cut the wire which exits the motor and is soldered to the fuse holder - cut it as closely as possible to the motor. Then undue the wire nut holding the other wire and remove it.

Now unscrew the old motor, screw on the new motor - it screws on with 2 small screws into the plastic frame, so be careful not to strip the thread on the plastic frame by overtightening the two screws.

Next connect either yellow wire from the new motor to the location of the wire nut and reinstall the wire nut.

Last - connect the other yellow wire from the motor to the wire that you cut which connects to the fuse holder or circuit breaker.

If you have no cracks in your gears and your controller doesn't keep track of time or move the large dial forward through your watering stations, chances are a new timing motor may cure the problem.

The other motor in your controller, the Advance Motor, only operates when you can actually hear the large dial indexing (audibly clicking) between watering stations or moving back to Rest. It is seldom active in comparison to the timing motor which runs continuously, so the Advance Motor practically never causes any problems. If any motor goes bad, it will be the Timing Motor 95% of the time. Be careful to select the correct motor, because motors are not returnable.

The Timing Motor has a short shaft that engages the controllers plastic gears, whereas the Advance Motor has a much longer shaft, so they are easy to tell apart. If your controller is plugged in, you will usually find the Timing Motor to be quite warm, even hot, whereas the Advance Motor is usually cold. This is normal and isn't an indication of a problem.

Can you change out the motor?  Sure, it's a 5 minute job. If you have doubts on your diagnosis, give us a call  at 352-683-3582  9-5, mon-fri. We'll be happy to walk you through determining the problem cause.

The Rainbird RC Series - RC4Bi, RC7Bi, RC1260Bi, RC4C, RC7C, RC1260C, were perhaps the most rugged and dependable controllers ever put on the market, and are still well worth repair.