I heard that too, but you can different brands...even directly from BMW. Cause that's where I got the plug & pig tails from.

I connected my dual lower temp switch in "parallel" to the stock temp switch. So if the lower temp switch fails, I have the stock switch as backup. Kinda like a "raid" setup on a computer.

No issue with thermo (no sure what you are asking), but it's been replaced with a 79c thermo.

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85' 190E w/collector plates