Need Help?

1988 Chevrolet S-10 Blazer Utility Base

1988 Chevrolet S-10 Blazer Utility
Do you own this car?
Estimated Mileage
 Miles
Enter current mileage for most
accurate info about this vehicle


Track Your Service Records
Get Recall Alerts
Get Updated Value Estimates on Your Car.

back to question list

Ask the Community

Ask Our Auto Mechanics


June 4, 2012, 11:28 am

Andrew B
 

Question: What would cause the voltage to drop significantly at 2000 rpms?

A few days ago my check engine light came on in my truck, but all my gauges read appropriately. The light came on with an accompanied electrical sound high pitch sound. The truck runs and drives smoothly with no error except when I hit 2000 rpm's the voltage drops to around 8-9 volts and my battery light comes on. I have had both the battery and alternator tested but both have come back as passed. I believe I have a malfunctioning voltage regulator, but I cannot get my alternator warranted unless it fails.

My vehicle has the 4.3 lt engine.


June 9, 2012, 2:16 am

Tyler O
Expert Mechanic

This does sound like an alternator issue. The voltage regulator is internal to the alternator.

Try retrieving the code from the engine computer if you can.

Most alternator tests can't detect a problem like you are describing.


0/0 users found this helpful.

Ask our panel of certified auto mechanics a question. We pay for their advice so you don't have to



My Auto Score

See the free AutoCheck score

Meet The Experts
Kim Perrin
Kim Perrin is our resident mechanic here at DriverSide. Kim worked as…
Tyler Orr
Tyler Orr is an expert in German and Japanese cars and has been a mechanic …
Elizabeth Kriesten
Elizabeth Kriesten worked as an automotive technician for several years at Dodge…
Tips on Servicing

Car Brakes: How Do You Know When to Change Them?

By Zach Bowman For those who suffer a daily commute through heavy traffic, your vehicle's braking system can bring thousands of pounds of metal, plastic and empty Starbucks cups to a stop hundreds of times before you get to work. It goes without saying that these pieces wear out, but they do so slowly, meaning you may not notice they need attention until ...

Read more…