There's other, more common causes of overheating, but given the recent service, it is indeed likely the belt is wrapped the wrong way around the water pump pulley. You can't physically do that on most engines but you can on some. One potential clue is the ribs on one side of the belt will always ride on ribbed pulleys. If you find the smooth side riding on a grooved pulley, or the grooved side riding on a smooth pulley, it's wrong.
As a side note, GM has had a really big problem with their generators since they redesigned them for the '87 model year, and they have no desire to fix them. They develop huge voltage spikes that can damage their internal diodes and voltage regulator, and interfere with computer sensor signals. The battery is the main thing that dampens and absorbs those spikes. Repeat generator failures are real common. In fact, it's not unheard of to go through six replacement generators in the life of the vehicle. To reduce that number of failures, replace the battery at the same time unless it is less than about two years old. As they age, they lose their ability to dampen those harmful voltage spikes. The old battery will work fine in a 1986 or older model.
Friday, September 5th, 2014 AT 7:58 PM