Hi @david24164
Unfortunately I cannot find a download online for a WRS588FIHZ04 (Whirlpool part # W11575236) or for that matter a WRS588FIHV06 (part # W11610658) either, so I'm hoping that the [document|35391|tech sheet] for a WRS588FIHV00 model uses the same diagnostic procedures to test the components in your model.
Enter the diagnostic mode a shown by the sheet and perform tests #44, #45, #47 & #48 and check the results.
If you find the problem and a different part needs replacing here's the [https://www.searspartsdirect.com/model/a7j81mpeg4-001198/whirlpool-wrs588fihz04-side-by-side-refrigerator-parts|parts list] for your model. Locate the wanted part in the list and note the ''manufacturer's part number'' that is listed with it. Search online for the part number only, to find suppliers that suit you best.