FRT18S6JS3 Refrigerator Not Cooling: Evap fan working, relay and capacitor tests checks out.

[raihansdg]

Model Number

FRT18S6JS3

Brand

Frigidaire

Age

6-10 years

Friends,

I have a Frigidaire, top freezer refrigerator which is just blowing room temperature air. I took the back panel off, took out the relay and the capacitor and tested them (continuity test for relay, ohm and voltage for capacitor) and they are working fine. I also tested out the thermostat and that seems to be working fine as well (continuity test).

The only thing left is the compressor right. So I did the scratch test to see if it is shorted/ grounded inside and it is not.
Then I performed a continuity test on the bottom two prongs of the compressor, I get a value that bounces from 300 to 20 ohms and does not beep. The top and the bottom right prong gives a value and beeps.
Does this mean the compressor is bad?

Also when I shook the relay it sometimes rattles but not constantly. It beeps for continuity test on all three inlets.

Any help will be much appreciated. Thank you



Oh by the way, the coils are clean, all the fans working, door seal is fine, the light inside the unit is working as well.

 

[Jake]

Hi,

Does the compressor make any sound at all when trying to start? OR is the compressor running and not cooling at all inside?

If the compressor isn't starting at all, or not even trying to start, test for 120 volts at the compressor start relay, if 120 volts is present, then you have a bad compressor.


The capacitor on your model is just a run capacitor, not a start capacitor, so that's not the problem.

PTC RELAY WITH RUN CAPACITOR
When the compressor circuit is first energized the solid state relay has low resistance 3-12 ohms and both run and start windings are energized to start the compressor. The run capacitor is bypassed by the relay. When the self-heating solid state relay has reached temperature it will change from low resistance 3-12 ohms to high resistance 10k-20k ohms and switches off the start windings. The only purpose of the run capacitor is to improve compressor operating efficiency.


Here's what Rick and Jeff also said on how to check your 3 compressor pins:

There are three pins in a triangle configuration. The pin at the top is Common. The pin at left is usually Start. The pin to the right is usually Run. Read between C-S and C-R

Use an ohmmeter to check the C-S: Ohmmeter should indicate between 3 and 11 ohms. Then check the C-R: Ohmmeter should indicate between 1 and 5 ohms. Then check from each compressor pin to the compressor body for a short.

If your having a problem finding the START and RUN windings pins on your compressor Read what Jeff says here:

First check to see if you have windings in the compressor. Then check to see if they are grounded. If the compressor has windings and they are not grounded, you can find which winding is which. Check for grounded windings by reading from each terminal to a good ground on the cabinet. Read from the top terminal to the lower left terminal. Read from the top terminal to the lower right terminal. Read from the lower left terminal to the lower right terminal. Write down the resistance of each reading as you go. The highest reading you get will be the run and start winding of the compressor in series with each other. The other terminal left will be the common terminal. Read from the common terminal to each of the other terminals. The terminal with the lower resistance will be the run winding. The higher resistance the start winding.

NOTE: IF you measure across S-R, ignoring the common. That reading should be the exact total of the two individual coil readings, because you're reading through both coils in series now. If those two sets of readings aren't within about 1/2 ohm of each other, then one of the compressor windings is shorted, and if it runs at all, it'll run hot and usually end up short-cycling on its overload protector.

Jake

 

[raihansdg]

Dear Jake
Thank you for your detailed response. Much appreciated.

Does the compressor make any sound at all when trying to start? OR is the compressor running and not cooling at all inside?

When I plug in the evaporator fan starts. After 10 seconds or so, I hear a click and the compressor turns on.

If the compressor isn't starting at all, or not even trying to start, test for 120 volts at the compressor relay, if 120 volts is present, then you have a bad compressor.

My multi-meter does not have the clamp for this test. Is there another way to do this? I will also do some research.

I will try out the tests for the compressor and get back soon.
Yes, the compressor does run hot. Once can touch it, but not for long. 5 seconds max may be.

 

[Jake]

You mean the condenser fan? The condenser fan is located next to the compressor. The evaporator fan is located inside the freezer.

My multi-meter does not have the clamp for this test. Is there another way to do this? I will also do some research.

You don't need a clamp for the meter, that's only for taking the amp reading.

You'll need to get a multimeter like this to check voltage to the compressor start relay properly:
Digital Multimeter

Yes, the compressor does run hot.

That's not a good sign, so if its running and running hot and not cooling at all inside you have a sealed system problem, either a burned out compressor meaning the piston inside the compressor is not pumping the Freon through the sealed system OR a sealed system leak and all the Freon has leaked out.

Jake