The rear window defroster on the CDI I just picked up is not working. The light comes on, the fuse is good, and the relay is good (swapped in the one from my other CDI). Haven't yet had a chance to run a scan. What should I do next in an effort to troubleshoot?

Thanks.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 157k miles
06 E320 CDI "Rutherford", Black on Tan, 175k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 70k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife