This is fairly easy. If you look at the top pully you will see a long screw, this is how you tighten the belt. First you must losten the bolt on the side of the bracket that holds the long screw, after doing so then you may tighten the belt. remember to re tighten the tension bolt or it will become loose again. It is the same for the other belt also.
Below is postscript to answer listed above by other donor:
Actually, you are half right. First you loosen the pivot bolt that goes through the base of the alternator. This bolt is accessible from under the passenger side wheel well. Then you loosen the bolt aiming horizontally through the alternator bracket, this bolt is up top. You then tighten the long bolt that is aiming diagonally to the ground. At this point, the bolt pushes away from the engine, tightening the belt. Next, tighten the horizontal bolt, then the pivot bolt from under the wheel well. I just love when people try to help, then give wrong answers like dude above did. Lesson, if you do not know, don't answer.
There is a tensioner bolt that is connected to the alternator. You have to screw in the bolt, which will pull the alternator out and tighten the belt.
Serpentine belt? You may have to remove to tighten alternator
Is the timing belt on a j30 infinity run the alternator
You will need to loosen the tensioner pulley. Put the alternator belt on. Push the tensioner pulley to the left until the alternator belt is tight. Tighten down the tensioner pulley.
To tighten the alternator best on a 240sx, loosen the bolt on the alternator on the drivers side. Pull on the alternator away from the engine to adjust the belt. When it has no more than a quarter inch of give, tighten the bolt to finish.
how do u tighten up an alternator belt on a 1987 BMW 325i?Answerhow do u tighten up an alternator belt on a 1987 BMW 325i?
depending on the style of belt, on the alternator belt there is an adjustment just below the slider holding the alternator, you just simply tighten it until belt becomes tight.
Loosen the tensioner pulley. The alternator belt will come loose. Remove the alternator belt. Put the new alternator belt on and tighten the tensioner pulley.
if the car doesn't have an automatic tensioner than if the belt is around the alternator pully you loosen the bolt holding the alternator on and move the alternator to tighten the belt.
You need to remove the old belt from the power steering pump. Then loosen, not remove the bolts on the alternator. Slide the belt over around and through the fan and onto the belt grove for the alternator. Then with a large bar push the alternator away so it tightens the belt. Later if not tight the belt will squeal. While putting pressure on the alternator tighten the bolts. Reinstall the power steering belt in the same way but you can tighten the belt on this one using hand pressure rather than the bar.
Loosen alternator remove old belt. Reroute new belt, tighten alternator.