On my '89 300SEL the engine/coolant temperature sensor/switch (the blue-bodied one that turns the aux. fan on when the engine is hot) is faulty.

I was thinking I would just pull the plug on it until I get a replacement. This will result in the fan running whenever the car is "on".

Are there any potential problems with doing this?

Of course, if there aren't any problems with doing this, it will significantly reduce my motivation for getting a replacement (until cooler weather hits anyway).

Thanks.
-Brett