Appliance Repair Questions? Ask a Technician for Answers ASAP
As I stated the motor does engage, the drain motor runs and the resistance to the wash motor and the main winding are in the range they should be... so I don't have any reason to think it is the motor.
Based on your reply it seems that you are suggesting that either the motor is bad, (which I do not have any indication of), or there is an issue with the "control voltage." What I would like from you is some detailed practical procedures that I can follow to accurately diagnose the problem and repair my dishwasher. Please help.
When the wash cycle begins p10 is at 121.8 v, p3 jumps to 3.7 v, p4 jumps to 13.9 v, and p5 jumps to 5.3 v when I can hear a hum from the motor. When the hum stops p3, p4 and p5 are at a constant 0.3 v.
When I cancel and the "drain" motor runs p10 is at 123.1 v, p3 is at 2.0 v, p4 is at 157 v, and p5 is at 3.2 volts.
Actually I think it is p7 that is the neutral, not p10, and my point in telling you the other readings was to show you that during the wash cycle there is no significant voltage to any of the motor windings and when the cancel cycle should put current through the drain winding, p5 there is instead a stronger than expected surge of voltage in p4, which is actually running the wash motor during the drain cycle... What is next?
I am not trying to get in a contest with you and I am sorry if I gave you that impression. I have never opened up or worked on a major appliance to the extent that I am attempting to with this dishwasher. I am simply trying to save myself the expense of buying a new dishwasher if this is something I can diagnose and fix myself. I have been trying for a week and a half using utube videos and other sites to gain some understanding of the inner workings of my dishwasher. I finally broke down and agreed to pay for the advice of an expert from this site. I do appreciate your help,I guess I have not been asking specific enough questions to get the advice I have needed. When I was checking the voltages I kept the black lead on the neutral (p7) or even against a grounding piece of metal... I will open it up again tomorrow and try it with the red lead on p4 and the black on p10 and let you know what happens.
Thanks. I'll check it in the morning and let you know. I guess I didn't really know how to use my meter....
ok, so here is what is going on now when I keep the black lead on p10... When it is in the the wash mode and the motor is making the humming sound p3 and p5 drop to about110 v and p4 drops to about 105 v. When the humming stops all three read 122.3 v. When I cancel and the drain motor is running p3 and p5 have a voltage of 119 v and p4 has a voltage of 54 v.
When I double checked the resistances from the circuit board from p10 to p3 was 2.2 ohms, p10 to p4 was 6.8 ohms and p10 to p5 was 2.3 ohms (which is too low). So I checked at the motor and when I checked again putting the leads into the clip on the motor I got about the same readings, but when I took the clip off and checked from the tabs on the motor where the clip with wires attaches I got the 6.8 ohm reading for the drain coil that is in the right range.... I have no idea why the clip would change the resistance...
Thank you for your help! I just ordered a new microcomputer.