I have a K machine w/ 18k hours giving me a flow error. I observe that the degass pump's shaft is spinning but the flow pump's is not. I swap plugs on the distribution board between the pumps and now the flow pump (plugged in at 20) runs and the degass (plugged in at 21) does not. So, I figure I have a voltage problem. I do a quick voltage check and I am getting 12 volts (Just like the manual asks for) at pin 1 of 21 and I get 24 volts (the manual calls for 16+) at pin 1 of 20. Since the flow pump supposedly runs half as fast as the degass, that sounds RIGHT to me. Im getting the voltages I'm looking for. Both pumps work when plugged into jack 20, neither run on 21. Could it be possible that the 12 volts just isnt enough to run it? I've tried it with a brand new flow pump and still no go.

We've also swapped Actuator boards, my last check is Actuator cable...but what is sticking in my craw is that I am getting the voltages that I should have, but pumpy no spinny.

Any advice would be appreciated.

Three words: power distribution board.
If you've tried replacing the actuator board and the actuator cable, that would be my next guess. Good luck.

I guess my concern is if the manual calls for 12V, I am measuring 12V... why isnt it pushing the pump? At my service school it was said that the pumps were electrically identical (i.e. swappable). Is that the concensus here? I believe they are different part numbers (not having a parts book handy)

Follow Long Hair. Your pump is not the issue. FYI, pumps are identical except for the brushes.

The pumps are identical but the wiring harness' are different. "KTECH" had a posting a few weeks ago describing the difference between the two. The connectors are wired differently

The plugs are wired differently also. A flow motor has it's wire soldered to pins one and five in the plug, and a deair is on pins one and three. If you plug a flow motor into the deair position #20 on the distribution board it will run because there is power supplied to both pins 3 and 5. If you plug a deair motor into the flow position #21 it will not run because there is no power to pin 5 there. So, if you change the brushes to the correct ones, and also change the wiring in the plug, or just change the whole wiring harness for the motor than Yes, it can be done.

I copied the above from "KTECH". It's not mine

Thanks Guest, TTech, and KTech. That is valuable info.

Did you check the brushes in the flow motor? If they haven't been replaced then they are probably worn out. Maybe they are worn enough that it won't run on 12 volts, but will run on the 24 volts that you get when you plug it into #20, the deair position? Or,the bearing could be going in the motor and causing it to seize up on the lower voltage and slower speed. Plug a known good FLOW (not deair) motor into #21 and see what happens. When you say you tried a new flow pump, do you mean the pump head, or the motor? I had replaced a distribution board just the other day and I forgot to plug the ground wire in that comes down with the heater wiring, well, the deair motor would just barely start to run and then stall right out, it needed that ground to run properly. The flow motor and every thing else that I know of ran OK even without that ground. And that probably is not your problem, but it was an interesting trouble shooting episode.

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