4wheelin
TYF Newbie
I bought my 1999 Yukon a few months back and have fixed things here and there. It currently has a red top Optima battery, age unknown.
My rig runs around 13 volts when driving with or without just the front a/c on. At idle, with the a/c on, it will drop to about 11 until I start moving again.
Now, if I turn on both the front and rear a/c it drops to the top of the orange area, or about 9 volts at idle, and goes back up to around 13 volts while driving, but when I come to a stop it will drop back to 9 volts pretty much every time. If I leave off the front a/c and only turn on the rear a/c only it still drops to 9 volts at idle all of the time.
If I turn just the rear defrost on and no a/c it will drop down to 9 volts until I start moving again. I know the defroster cycles the a/c compressor.
I'm new to having a front and rear a/c. Is this normal? I think sitting at a stoplight with the battery gauge reading 9 volts is fairly low. Maybe not though. I just don't want to get stranded for something as simple as a battery or alternator. Before I go and have them tested I wanted to see what others know on this subject.
My rig runs around 13 volts when driving with or without just the front a/c on. At idle, with the a/c on, it will drop to about 11 until I start moving again.
Now, if I turn on both the front and rear a/c it drops to the top of the orange area, or about 9 volts at idle, and goes back up to around 13 volts while driving, but when I come to a stop it will drop back to 9 volts pretty much every time. If I leave off the front a/c and only turn on the rear a/c only it still drops to 9 volts at idle all of the time.
If I turn just the rear defrost on and no a/c it will drop down to 9 volts until I start moving again. I know the defroster cycles the a/c compressor.
I'm new to having a front and rear a/c. Is this normal? I think sitting at a stoplight with the battery gauge reading 9 volts is fairly low. Maybe not though. I just don't want to get stranded for something as simple as a battery or alternator. Before I go and have them tested I wanted to see what others know on this subject.
