The day I finally saw what a bad compressor start relay looks like

I've been doing appliance repair for about 6 years now, and last Tuesday I had a fridge call that finally made it click for me. The customer said their freezer was cold but the fridge section was warm, which is pretty common. I've swapped out start relays probably a hundred times without really thinking about it. But this one had this weird charred spot on the plastic housing, not melted but definitely discolored. I pulled the old relay and compared it to a new one side by side, and I could actually see the difference in the contact points inside. The old one had this pitted surface while the new one was smooth and shiny. Now I'm wondering if half the relays I've swapped were actually bad or if I just assumed they were. Has anyone else seen this kind of pitting on a start relay and known for sure it was the problem?

3 comments

3 Comments

sean_torres7117d ago

Whoa, @jesse_williams62 actually made me rethink a few relays I swapped without checking amp draw first.

jordan90318d ago

Stick a multimeter on the next one you pull. That pitting you saw is arcing damage. I've had relays test fine with resistance but fail under load when the compressor tries to kick on. The charred spot is a dead giveaway the contacts were burning up. If you see that discoloration, it's bad. Don't second guess yourself on those.

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jesse_williams6218d ago

Whoa hold up, I gotta push back a little on that. I get what you're saying about the pitting and arcing, but I've actually swapped in brand new relays that had the exact same issue after a week because the compressor was pulling too many amps in the first place. The charred spot is a symptom, not always the root cause you know? If the relay tests fine on resistance but dies under load, sometimes the real problem is a failing start capacitor or a dying compressor that's drawing way more than it should. I've saved myself a headache by checking the amp draw on the compressor leg before blaming the relay every time. Not saying you're wrong, just that I've been burned by swapping parts that weren't actually the problem lol.