Dishwasher spray arm not spinning

[beachbum]

I have a Frigidaire Ultra Quiet III model FDB750RCQ0 dishwasher that I got used. The center spray arm doesn't seem to ever move. I even started a cycle with the door cracked open, and the bottom one spins and sprays, but the top one was just sitting there.

Looking at the dishwasher itself, and at the parts diagram at ftp://ftp.electrolux-na.com/ProdInfo...5995386694.pdf, I can't tell how it ever would spin. It looks like a gravity fed funnel, about 6" from the top nozzle to the funnel that feeds the spray arm.

I tried taking the top tray outside and running water into the funnel. The spray arm sprayed water, but still did not spin.

I got started on this because the dishes on top aren't getting clean. Should I be able to see the arm spinning?

Thanks!

[Dan O.]

Frigidaire dishwasher model FDB750RCQ0. The center spray arm doesn't seem to ever move.

Looking at the dishwasher itself, I can't tell how it ever would spin.

The control mechanism stops the pump at certain points during the cycle which allows the 'check ball' inside the pump to change positions which in turn allows one or the other spray arm to be fed with water.

I tried taking the top tray outside and running water into the funnel. The spray arm sprayed water, but still did not spin.

It is the water pressure alone that causes the arm to turn. As long as it was getting sufficient pressure it should be turning or it or the part it connects to might be worn and binding, hampering its movement?

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[beachbum]

Dan, Thanks for the info.

It is the water pressure alone that causes the arm to turn. As long as it was getting sufficient pressure it should be turning or it or the part it connects to might be worn and binding, hampering its movement?

I took the assembly apart. There is the spray arm that mounts underneath the upper tray and through the base. Also, a plastic threaded nut with teeth that secures it on top of the tray and base. A funnel snaps over the top of all that.

When it's all assembled, the arm spins freely. I tried the hose approach again, and was able to get the arm to move a little bit when I forced a lot of water through the funnel with the hose right at the mouth of the funnel.

Maybe the nut with teeth is wore out? Is that how it is supposed to turn?

It still seems weird to me that water falling out of the top nozzle and into the funnel would create enough pressure to spray back up at the tray, and spin the arm.

[Dan O.]

** Maybe the nut with teeth is wore out? **

Maybe. I couldn't find a picture of a new one on-line for you to compare yours to, sorry. Maybe you can find a local appliance parts dealer with one in stock you could look at?

** seems weird to me that water falling out of the top nozzle and into the funnel would create enough pressure to spray back up at the tray, and spin the arm. **

The water at that point I would think should be under more pressure than "falling out"

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[tina ryan]

hi, I'm Tina, I have a Frigidaire who doeen't work I don't know why, I want to know at least for something who knows a little abut that

[HayZee518]

please go to this site www dot partselect dot com - type in your model number. this will take you to several exploded diagrams of your machine with parts references and a parts list. I looked into the motor and pump diagram and got a better idea of what you were speaking about.

[beachbum]

I looked into the motor and pump diagram and got a better idea of what you were speaking about.

Thanks, the spray arm from that diagram fits through the upper rack in the rack diagram. The nut I'm talking about fits between parts 8 and 9, but I don't see it listed.