Staff Answer
Sep 24, 2026 - 06:41 PM
A fault light right after a board swap on electric usually comes down to a few things. Double check the AC heater and fuses first. Measure the AC heater resistance (unplugged from the board). A good heater will read a steady resistance, while an open reading means the heater is bad. Also check the fuses on the new 639593 board, and confirm you have 120V AC at the outlet and at the board. If the heater was bad on the old board, it can take out a new one the same way.
Our Norcold error codes page explains what each light means, and here's our guide on RV refrigerator not working on electric. If you're still stuck, our tech support service can walk through it with you. The AC heater for the Polar models is the 638374/ 50822. If you have any questions, just reach out at info@rvfridgeguys.com or call us at 800-712-8822. You can find everything we carry at www.rvfridgeguys.com.
