I have a 2004 A4 Convertible with @117K miles. I've owned for 2 years, no issues. I drive it to work @ 2-3 days per week, so not daily, but not garage queen. 3 days ago drove to work and around town. No issues.

This morning, get in and start the car. The DIC has "Low Voltage". I look at the Volt gauge and the needle has not moved at all. I turned the car off as I would not risk it going to and from work.

Unfortunately, that is what I know right now. I have looked through the threads and google. Many people seem to have other problems associated before they get the light. The battery is newer and starts the car fine, no other indications of anything wrong with the electrical system. Just looking for insight. My gut is the alternator. Are there any relays or fuses that I should check. Since this is an all of the sudden problems, it makes me leary of assuming the alternator.

Thanks.

 

Did you try to start the car? There are a lot of reasons why you would get a low voltage (accessories left on?) reading. Remember that your car has a lot of systems that remain "on" after the key off which pulls energy. Plus, we are in full summer and heat will make a weak battery worse.

Don't throw parts at your car. Get her started and take her to Auto Zone and have them give you a free electrical system test. You will know right away what needs fixing.

 

The car started up like normal this morning.
The DIC showed Low Voltage. The voltage meter gauge did not indicate anything. I revved the engine to see if the indicator would work, but it did not move. No more time to diagnose.

 

When is the last time you cleaned your grounds?
https://www.corvetteforum.com/forums...tion-long.html

 

The first thing is having your battery load tested…if good and you have a DVOM see what your battery voltage is AT the battery and then check it from the alternator B+ and ground (alternator case is a good ground)…if battery is charging anywhere from 13.5 to 14.3 or so what gives you that warning is the IPC detects less than 10 volts for more than 5 seconds…the IPC gets it voltage for this message at the “Ignition 1” voltage coming from the IPC fuse 19 at the IP fusebox…if the message appears read the voltage at either of the 2 test points on top of the fuse and compare that voltage to the battery voltage…this may be the start an ignition switch issue but more testing may be required.

 

Thanks everyone. Crisis averted. All seems well now.

I got home from work and check again: ignition on, all gauges sweep across. After a few seconds, the low voltage warning came up on the screen the gauge showed 0. I have a USB charger port with Voltage reader on it, it showed 11.8V. I started the car and voltage on the USB reader dropped to 10.4 and came back to 14.0. The gauge in the car showed nothing, and the DIC reading was 1.3V. So, one indicator at 14.0 and another at 1.3. I tend to trust the car gauge more.
I removed the battery and took it to an Advanced Auto parts, they put it on the machine for about 20 minutes. The guy (who I had little faith in) said the machine checks and charges the battery at the same time. Upon my return, the guy said that "it checked OK." I asked what that meant. So he punched some buttons and said, "Yeah, it's 492." I asked "492 of what?". His reply, "I don't know, but the machine did not say it was bad. So, it's good"

I left there and went to an Orielly's down the street. They put it on a simple tester and the machine showed battery pass. I returned home, cleaned the battery terminals and installed the freshly charged battery. Now, everything works. Perhaps a loose connection, low battery state, or something. On my test ride, voltage stayed at 14-14.1. I keep a closer eye on it for a while.

Thanks again.

 

Well, drove to work today with no issues. At lunch, i ran up the street and back and the coolant gauge spiked. I shut it off and check, no smells or anything out of the ordinary. After work, started up and again, instantly pegged on the coolant temp. Drove home with no issues. Put it on the lift and checking connections. Nothing loose or corroded looking.

Clearly, there is an electrical gremlin.