RUUD mod number urma-a024jk08e not cooling house. Condensing fan want start turning on its own, but will run if I get it started. Blows cool but not cold air. Not sure if transformer could be the cause or if something else. I need to know what voltages I should have on the transformer and the cap and the contactor.

How are you getting it started? Pushing in compressor contact or manuall spinning fan?

Sounds like you need a new compacitor to me