Finally figured out the real trick for diagnosing bad compressor start relays

I kept seeing guys on here swapping out whole compressors when the fridge wasn't cooling. Turns out I was replacing start relays wrong too for like 2 years. Last week I had a Whirlpool side-by-side where the relay was clicking but the compressor wasn't kicking on. Used my multimeter to check resistance across the run and start windings - found the start winding was open. Ordered a new relay for $12 instead of a $200 compressor replacement. Saved the customer a ton of money and felt like a hero lol. Anyone else have a simple test that caught them slipping for way too long?

2 comments

2 Comments

beth_baker6921d ago

Man, the multimeter trick is a game changer. So many guys just swap parts without testing first. Start winding going open is super common on those Whirlpools too. Another one that got me for years was the overload protector. If it's weak but not dead you get that same clicking but no start. Checking resistance cold then warm caught me slipping. Now I always start with the meter before touching anything else. Saves you from looking like an idiot when the new relay does the same thing.

ivan8221d agoOG Member

The one that got me was checking the PTC element inside those old relays. They look fine on the outside but the ceramic disc cracks and loses its resistance when it heats up. Used to toss them in the freezer for ten minutes to cool them down, check continuity hot, and watch them fail the test. Two dollar part, ten minutes of fiddling, saves another compressor swap.