KFIV29PCMS00 Compressor doesn't turn on

[dorje]

Model Number

KFIV29PCMS00

Hi,

My freezer wasn't freezing and everything melted, including the ice in the ice bin. The issue was intermittent for a while, then it went out altogether. I can hear relays clicking to turn the compressor on from the control board, but it doesn't do anything.

I used this post to check out a few things. Kitchenaid KFIV29PCMS00 not cooling

Rather than 3-6VDC, I'm getting an even 7VDC at the red and black wires at P8 on the control board. I'm also getting an even 7VDC at the red wire harness that plugs into the inverter. I ohmed out each of the three pairings on the compressor and they were a little over 9 ohms each. I also tried the cabinet ground from each compressor terminal and am getting an open circuit.

Is there something else I can test? I'm suspicious of the inverter, but I don't really have an easy way to test it. I called my local repair shop, but it will be a couple of days before they can get out.

Thank you for any help,
Erik

 

[Jake]

Hi Erik,

Did you get 120 Volts AC between the BLACK WIRE and the WHITE WIRE?

If so, and your getting 7 Volts DC between the RED WIRE and the BLACK WIRE at the inverter, I need to ask Rick to confirm is 7 Volts DC is too high, rather than 3 to 6 Volts DC.

Here's the inverter for your model:
W10893917 Invrtr-Box


Jake

 

[rickgburton]

I ohmed out each of the three pairings on the compressor and they were a little over 9 ohms each.

Erik, recheck your compressor windings. Whirlpool says they should be 6.4Ω ± 15%. The compressor might be causing the higher signal voltage.

 

[dorje]

Thanks Rick and Jake. I was able to get someone out here today from across town. They say it's the inverter and it's not putting out 230VAC. I tested it myself after he left and am getting only 30VAC.

I went back and I tested the windings again and I was mistaken the first time. I was getting a consistent 6.8Ω. I went back and checked the Red and Black pins on P8 and am still getting 7VDC. The technician said he was getting 6, so I went around checking a few wall warts for DC output and everything seems ok, but I won't have another multimeter or a bench power supply to test against until Monday. I checked between the Black and White connections and am getting 118.7VAC.

 

[rickgburton]

I went back and checked the Red and Black pins on P8 and am still getting 7VDC.

Connector on or off?

I tested it myself after he left and am getting only 30VAC.

Connector on or off?

 

[dorje]

Red and Black had the connected off and tested on the control board pins. The connector was disconnected as well on white and black. The inverter side had fluctuating mV, so I assumed discharge or something. The other side measured 30VDC. I didn't see if the tech tested with them connected or not. I don't have insulation piercing probes and I'm not sure how to safely measure inline.

 

[rickgburton]

Red and Black had the connected off and tested on the control board pins.

You need to measure the voltage with the connector on the board connected. Voltage should be 3-6 VDC

The connector was disconnected as well on white and black.

It doesn't matter if it's connected or not. There should be a constant 120 VAC at the inverter all the time.

The inverter side had fluctuating mV, .......The other side measured 30VDC.

You lost me here, sorry. The inverter side of what?

I don't have insulation piercing probes and I'm not sure how to safely measure inline.

Go in through the back of the connector. Be sure your meter test lead is touching the metal wire end in the connector. If your meter leads are too big to go into the back of the connector use my safety pin trick:


Don't overthink this. It breaks down to this; The compressor windings are correct so you need two voltage measurements, 120 VAC constant at the black and white wires and 3-6 VDC constant when the machine is calling for cooling. I wouldn't worry about 1 VDC. The signal voltage is a square sine wave and many less expensive meters can't read the voltage correctly. If the voltage is correct and the compressor doesn't run, bad inverter. If the signal voltage is not 3-6 VDC, bad board. If the supply voltage is not 120 VAC check for a broken or pinched wire between the power cord and the inverter.