I have replaced the pump and motor assembly and installed air gap. it wont drain completely. it leaves about 1/2 inch of water left in the bottom of d. washer.

Hi,

I have pretty much the same exact problem on my GE Dishwasher GSD2230Z04WW. I replaced the motor pump and assembly and now when I did the test run (rinse and hold cycle), it leaves about an 3/4 of an inch of water at the bottom when it is complete. I cleaned the air gap, checked the drain pipe and it all looks clean now...i did had to clean the air gap.

I diconnected the drain pipe from sink disposal to a bucket and ran the cycle again still have the same problem.

The solenoid also seem to pull all the way low during drain cycle. I am at loss and can use some tips that I can try.

I had the same problem. The dishwasher would run, and at the end of the cycle there was water still inside the machine. I'm not an appliance expert, but I just went through some troubleshooting. You said you disconnected the hose from the sink to the bucket on the dishwasher. I did the same thing and took a video of doing it because apparently its a common problem. I think in your case, the hose isn't clogged between the sink and machine, but rather after the sink. If you have a food disposer, or even in the absence of it, I often found that accumulation of the machines byproducts became adherent after the hose-sink junction. I disconnected all of them, and it was clear that one part in the networking of the hoses was more prone to byproduct accumulation and clogging. The clog was white in color and tough. This stuff builds up over time, almost like someone's artery, and once clogged, your best bet is to throw it out, and get a new hose. Its a cheap solution, and is usually the cause. 30,000 ppl watched my video on dishwasher repair, and a lot of them reported the same issue and solution. Feel free to watch it. ....
https://www.youtube.com/watch?v=u7uaA2NZKl0

I do have a question, forget the arm in the bottom, because that's unlikely. Believe it or not, its not usually food clogging it up, but rather the soaps. Is your machine older than 2 yrs?