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jamesleehart

testing a compressor relay

11 posts in this topic

I have an Electrolux lffu2065dw6 freezer.  It is put out as a Frigidaire.  I need to know how to test the compressor relay and compacitor.  I have power to the relay wires but the compressor will not come on.  There are 3 prongs on the compressor where the relay plugs in and so there are 3 holes on the relay itself.   Is there a way to test power coming out of the 3 holes?

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I do not test this type of relay by checking its voltage output. Normally, I would do the tried and true shake test (shake it, if it rattles it's bad). If it doesn't rattle, I would try a used compatible relay that I know is good. If the compressor starts (usually it's in run mode) I know the run winding on the compressor is okay and there is no mechanical problems. I would then unplug the fridge and plug it back it and wait for it to come on in the start mode. If it comes on, then I replace the relay with a new one.

If the compressor doesn't start (make sure the compressor isn't too hot as its thermal protection will prevent it from starting) I test the compressor windings and check for short to ground.

Since you probably don't have compatible relays hanging around, simply do the shake test. If it doesn't rattle, test your compressor. If it passes then buy a relay from repair clinic. If it doesn't work, get your money back.

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The relay can show power through and still be bad.

Many relays that are bad will rattle when you shake them.

As Master Reg stated...test the compressor,if the pins read good,the relay is probably bad.

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The ohmmeter test was good.  The relay does not rattle.  I do not have one of those test cords and am not sure how to make one.  Like I said, I am getting power to the two wires that plug into the relay so that tells me that it is either the relay or the compressor.    Would the compacitor have anything to do with it?

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...I am getting power to the two wires that plug into the relay

tested while everything is still connected ?

(should be)

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I rarely find a bad capacitor. Testing depends on the type of meter you have. Here is a youtube video for testing using an analog meter. You can find other videos to show you how to do it with the type of meter you have. Make sure to discharge the capacitor first.

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James, I've had few Frigidaire upright freezers that I've had to replace the relay on.  Same symptoms and signs.  Relay checked good with the ohm meter.  No visible or audible (shaking) damage indicated.  As long as the compressor windings ohm ok, replace the relay.

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The capacitor is a run capacitor and will not affect the starting of the compressor, sounds like a bad relay. I believe the relay you have is not the standard PTS relay and doesn't normally rattle when bad.

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Well, I ordered a relay and I will see what happens.  Everything else seemed to check out fine.  Thanks for all of the responses to my call for help.

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This is my experience, Freezer compressor would not start.Took the start relay to an appliance repair shop, checked relay (that rattled)with an ohm meter and it checked good.He showed me a new relay and it rattled too.By that I decided not to buy a new relay if mine was good. Came home and used my test cord and the compressor started just fine.Because I hated to loose more food by taking a chance I went ahead and bought a new freezer.I intended to keep my old one and check it out further but the delivery man came 2 hrs. early and had already hauled it away.If it were me I would try a new relay,if it works great and if it doesn't you're out $20.00.At least you won't feel bad like me.

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