you need to get a tool referred to as a "syrpentene belt wrench" you can rent them from most auto zones, or pick one up for about 25 bucks.
If it is a serpentine belt, the tension is automatically adjusted by the tension idler. If the belt is loose then the tensioner needs replacing. If it is a normal drive belt, then the alternator is mounted on a slotted bracket that allows you to adjust the position of the alternator. You can loosen the bolts and adjust the tension on the belt.
Loosen the alternator tensioner bolt. You will be able to slide the alternator either way to adjust the tension on the belt.
The alternator is rotated on it's pivot to adjust belt tension.
Apply a wrench to the center bolt on the pully and turn it will adjust the tension.
If it is a drive belt and not a serpentine belt is has no tensioner. You manually adjust the tension by normally adjusting tension by moving the alternator. Loosen to bolts holding the alternator in place and then adjust the tension. Tighten the bolts when the tension is right. If it is serpentine belt if you follow the belt around the the engine you will see the tensioner.
where is the location of tensioner of 2002 3.1 L Chevy Malibu to adjust if replacing the alternator?
Yes, it is used to adjust the tension on the A/C compressor. Looking into the engine compartment from the passenger side it is to the left of the alternator. To adjust tension you need to loosen the bolt which holds the pulley and then adjust the bolt which is directly above the pulley. Once you have proper tension tighten the pulley bolt.
If the alternator is driven by a drive belt, the answer is yes. You adjust the tension by loosing the bolts on the alternator mounting brackets and sliding the alternator until the proper tension, (around 1/4" deflection at mid point of the belt) is achieved. If however it has a Serpentine Belt driving the alternator, then there is no adjustment. Tension is held by the idler pulley. If it is loose then the belt is worn out, the idler tensioner is defective, or both.
You move the AC compressor and the alternator to adjust tension. Has to be done from under car.
You'll find an idler/tensioner pulley, which rides on an adjustable arm. First you have to loosen the locknut(14mm?) of the pulley , then tighten/loosen the adjuster rod (8mm?) to adjust the belt tension. Afterwards, tighten the locknut.
The first thing to check is your fan-belt tension, if it's loose it will slip and not drive the alternator efficiently. Adjust/tighten it as required
There are two bolts to loosen to adjust the alternator belt tension. 1st is the adjustment bolt. 2nd is the pivot bolt It is easiest to get at them from the bottom of the engine on the passenger side rear of the engine.