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My trans runs a little hot while towing, around 200. I wish I could have an in cab switch so that I could engage the electric clutch on the cooling fan to pull some extra air past the trans cooler when towing. It would also be nice when idling with A/C on in the Texas summer. Surely it is just a 12v feed or a grounding of a circuit that engages the clutch. If anyone know please help me out.
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You could, but it'd set codes. The Visctronic fan drive has a speed sensor that provides closed-loop feedback and if it's showing that the fan is turning significantly faster or slower than requested, it'll set a code.
Now, that said, 200F ATF temp isn't anything to worry about. The specs say 221F is the max long-term sump temp (if you're in the pressure port for your sender, that's close enough), with up to 248F allowed for short runs, say 30-45 minutes while pulling a big hill with a big trailer. If it was my truck, I wouldn't worry about 200F at all.
Okay, thought experiment time. I'm thinking of a couple of numbers. One is 1XY, the other is 2AB, where the letters represent additional digits. If you were running a digital temperature gauge for an automotive fluid of your choice, which number would prompt you to concern, 1XY or 2AB?