Near the top of the engine is a tensioner assembly. The pully can be pushed back using a breaker-bar and the appropriate sized socket. Note the layout of the belt before removing it because there won't be much help if you can't figure out how to put it back. For the record, all GM vehicles since mid 50's have been 12 volt.
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The belt tensioner pivots with spring tension against the back (smooth) side of the belt. The tensioner arn has a molded square hole in it - this hole takes the end of a 3/8" drive socket wrench, which you then use as a handle to give you leverage to go against the tensioner spring with one hand, while removing the belt with your other.
change in voltage from no load to full load
Very easy. Disconnect the battery. Lift up the belt tensioner and slip the serpentine belt up off the alternator pulley. Remove the 3 bolts holding down the alternator. Unplug the voltage regulator cable from the alternator. Disconnect the positive battery cable from the alternator. Installation is the reverse of removal.
The 1998 Chevrolet Astro Van voltage regulator is part of the alternator. The voltage regulator cannot be individually changed. You will need to change the entire alternator.
The voltage regulator on a 2004 250 Trailblazer is integrated into the alternator. Because of this, to change the regulator, it is easiest to replace the entire alternator.
change alternator
The AVR (Automatic Voltage Regulator) control the DC field voltage to the rotor of the alternator, as soon as higher load is demanded from the alternator, the AVR output voltage go higher, hence, a higher AC voltage on the output of the alternator. If the voltage go to high then the AVR is faulty.
To change the voltage regulator on almost all modern GM cars, replace the alternator. The regulator is inside the alternator, and is not considered a field servicable part.
Disconnect the battery negative terminal. Remove serpentine belt. Remove bolts to alternator and positive cable at alternator and harness. Remove alternator. Reverse procedure to install.
Disconnect the battery.Remove the serpentine belt.Take off the wires on the back of the alternator.Unbolt the alternator from the engine bracket.
You need to remove the serpentine belt and unbolt the old alternator. Bolt on the new one and reinstall the belt. Its that easy.
on the alternator on top is a bolt losen that bolt and it will allow you to move alternator causing belt to losin
First thing is to look at the bottom passenger side pulleys. These cars have a serpentine belt ( 1 belt for all pulles ). There is an Idler pulley that believe it or not bends when you try to loosen it off ... this tensioner will allow you to change the belt and alternator ... before you change the alternator get someone to look at it it could be just the Voltage Regulator 40 roughly to replace ( It is located on the back side of the Alternator ).