Instead of a Klima relay, it and other relays were combined into the MAS (silver box with a knob in front of the battery). Turn the knob to the "0" position to be able to remove it. "I" position to install it. On my son's 1990 300E, it also wasn't getting power, even though I had 12v when I jumped the two leads from the a/c low pressure switch (at the top of the dryer). You local pick n' pull has one for $20 or eBay for $35. Let us know what you find.

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03 CLK430 Cabrio 211K Pweter Silver/ Oyster Leather
90 300SEL 214k Pearl Black/ Alto Grey/Black Leather

Prior: 85 190E, 88 300TE, 89 300TE, 90 300E 2.6, 90 300TE, 92 300E 2.6, 91 and 93 300SL, 87 Ferrari Mondial Cabrio