not technically. The serpentine drives the pulleys under the hood. The fuel gauge's float is located in the fuel tank. So no, but if the serpentine belt is off long enough it could affect it if the battery level got too low. But the car will die long before that happens.
Replacing the water pump and belt should not affect turn signal operation.
no. no relation at all
Check the serpentine belt or Thermostat stuck.
No, an accessory belt is not considered a serpentine belt. However, a serpentine belt is considered a specific type of accessory belt.
No. The timing belt is under the timing belt cover and drives the water pump, oil pump, and cams from the crankshaft and is necessary for operation of the engine. The serpentine belt is on the outside and drives the alternator, power steering, and air conditioner.
The serpentine belt and the tensioner on a 300 SE motor is part of the fan system that controls all of the smaller motors on the front of the engine. The serpentine belt helps turn the alternator, power steering pump, water pump, and the fan. The tensioner is a pulley on this belt that helps to keep the belt tight enough to stay on, but not too tight to hinder operation.
Look in the engine compartment for the "serpentine belt" path & tensioner diagram. Release the belt tension at the tensioner, remove & reverse operation.
The serpentine belt would be the same as the accessory drive belt.
Serpentine Belt Diagram ML320
Serpentine belt, no. Timing belt, good chance yes.
If the alternator belt is the same belt as the other accessories, yes.
That I know of, there is NO serpentine belt, unless you are talking about the the Timing Belt (hardly serpentine, but anyway), it has a belt tensioner, not automatic, though.