The 2004 Chevy TrailBlazer may experience alternator load issues if the voltage regulator has started to fail. As part of the charging assembly in the Trailblazer, the entire alternator must be replaced if the VR is going bad. Signs it needs replacement include headlights dimming and brightening while sitting at idle, a discharged battery after engaging both heat and lights, and any drop in battery power while using the Trailblazer's accessories or climate control features. If the VR is not doing its job Your alternator may over or under charge the battery and these conditions will result. Most regulator's are set to maintain an output of between 13.5 volts to 14.5 volts of power. Your Chevy requires between 12.8 to 14.0 volts to protect its electrical circuits and parts while charging. Cost to replace the VR averages $400 in parts and labor.
Kim
May 12, 2022
How do you knowhow to change it myself
Edward K
July 16, 2020
If the 2004 Chevy trailblazer is having issues with the battery, they could be caused by a few things. A bad alternator will cause it to not charge, as can a bad battery cable. The battery itself could also be dead. Any of these issues will lead to electrical issues or will cause the vehicle to not start.
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