On my 07 LT I have noticed a couple times while driving that the battery voltage gauge will drop to about 13 volts. Most times it will show a little past 14 volts while the engine is on. It happened again this morning, so I turned the truck off, turned the key so that the accessory power was just on, and it was at 13 volts (just like it was when the engine was on). Started the truck again and it jumped up and held past 14 volts (normal). Does the new Tahoe intermittenly charge the battery or do I have a bad gauge or something worse?

 

mine varies with engine speed. At idle its approx 13v and as rpms increase so does the voltage. seems like the batt voltage/charging increases and decreases with engine rpm

 

I checked that. This was staying constant 13 while running at 55 or at a stop light. The peculiar thing is when I shut it off and turned it back on again it went back up to charging at 14+.

 

Your alternator is only engaged when the computer feels it's neccessary. This helps create more horsepower by not dragging down the engine.

 

I think you might want to have the dealer service look at that. I have never noticed the charging not vary with engine rpms on mine. Maybe dave will chime in on this and offer some expert advice!!

 

Nevermind.............. seems logical Jason! Guess mine just likes to vary with engine rpms because I always have the a/c, stereo etc. running all the time.

 

That is what I hoped was going on. Thanks jason75.

 

My gauge is all over the map also.

RPM's, Lights, AC, Stereo, wipers, etc cause it to fluctuate!

 

My gauge is all over the map also.

RPM's, Lights, AC, Stereo, wipers, etc cause it to fluctuate!

 

This was actually discussed before and I'm pretty sure Jason and Dave agree on this - charges as necessary.

Found the thread:
https://chevroletforum.com/m_5867/tm.htm