Hi,
I am trying to repair a Frigidaire dishwasher model FDB 4315 LFB0. The problem we've been having is that the motor runs and won't shut off unless the door is open. It runs through all the cycles and the motor unit will not complete the wash cycle and shut off ( it;'ll literally run as long as the door is closed). The unit is getting water, and is heating and appears to run through the cycles, and the water is spraying. It's just that the motor just runs and runs no matter what as soon as the door is closed . The cancel / drain cycle has no effect on the motor running. I've cleaned all filters and there does not appear to be any blockage from inside the tub. The drain pump is working also. One thing I did notice is that it is spraying water all the time as well.
I've tried to "reset" the unit by turning off circuit breaker for a few minutes , then turning back on , but I still get the same results.
So yesterday I found and downloaded the Electrolux Fully integrated Direct Feed Dishwasher Service manual and run it through the following self diagnostic tests:
Water Service Test: (as stated since the motor won't shut off, it ran through all phases of test).
- · Only failure was during the Dry cycle and received code rA : which means Rinse Aid (" the control has sensed a problem with the reed switch in the Rinse Aid dispenser")
Water Temperature Test: ( again motor ran through entire test)
- · Water temp was registering from 94F which appears correct temp for the inflow water.
Relay/Triac and Sensor Tests:
- · Active water valve: normal
-
- · Test Variable Speed motor ( through 4 speeds and shut off): would only read 35 on display ( i.e. 3500 rpm motor speed) through all 4 speed tests . There was no variation in motor speed. Also this test would not terminate and motor continued to run.
-
- · Heater on/ off: normal
-
- · Detergent dispenser: normal
-
- · Rinse aid level : normal
-
- · Drain pump: normal (pump cycled)
-
- · Vent/ Fan dry: normal ( variable speed (rpm's) registered as fan turned on and off)
-
- · Soil sensor: normal ( I think this registered 46, but I didn't write it down, so just a guess)
-
- · Thermistor: normal (94F registered)
Also, I pulled the control module out and inspected the circuit board for any signs of burnt or broken circuits or wires and everything looked physically OK.
First I know it threw a Rinse Aid code indicating the reed valve was not functioning properly. There was rinse aid in the unit, but I filled it up just in case and ran the test again and still got the same fault code. Could this possibly be causing the problem ? I wouldn't think so , but what do I know. Frankly I am really not concerned if the rinse aid doesn't work as we use those detergent "pods" now that have rinse aid integrated in them. But , if it is a possible culprit, I will replace the bad part.
So, aside from the Rinse Aid issue, I am thinking there is either an issue with the Variable speed motor circuit ( i.e. the switch that controls the motor , or the motor itself) . One thing that was not tested in all of this was the float switch, which as I understand controls the inflow of water. I think this is OK, but I'd like to test it to make sure. Can you advise how to test the float switch?
Also , I do not see a separate timer anywhere on the unit, is it safe to assume this is found on the circuit board? The timer does start at 93 mins for normal wash cycle and runs down as it cycles through, but it still doesn't shut off after it reaches then end of cycle .
Can you advise how to determine definitively what is wrong with the variable speed motor that is causing it to run constantly? What controls it's "variable" speed setting and what turns it on/off? Is it a physical switch , or something on the main circuit board? Is there a way to test the motor standing alone?
I intend to fully pull the unit out tonight to get at the components on the bottom and side to inspect and test them, but would really appreciate any guidance you might be able to provide.
Thanks
Guy
