Locate the alternator belt. It is located on the front of the engine, running between the alternator and the crankshaft pulley.
Loosen the alternator mounting bolts. There are two bolts that hold the alternator in place. Loosen these bolts just enough so that you can move the alternator.
Move the alternator to tighten the belt. Use a pry bar or other tool to move the alternator towards the engine block. This will tighten the belt.
Re-tighten the alternator mounting bolts. Once the belt is tight, re-tighten the alternator mounting bolts.
Start the engine and check the belt tension. The belt should be tight enough so that it does not slip, but not so tight that it puts excessive strain on the alternator bearings.
If necessary, adjust the belt tension. If the belt is too tight or too loose, you can adjust the tension by moving the alternator again.
Here are some additional tips for tightening the alternator belt on a 1989 Toyota Pickup:
Make sure that the new belt is the correct size for your vehicle.
If the alternator belt is old or worn, replace it with a new one.
If the alternator is not properly aligned, it can cause the belt to wear out prematurely.
If the alternator is not charging properly, it can also cause the belt to wear out prematurely.
