Low Voltage
Thread Starter
Cruising
Joined: Sep 2020
Posts: 11
Likes: 1
Low Voltage
Hey guys last time I posted here I got some awesome advice so I am hoping you can help me out again.
I have a 2000 c5 and recently have been having an issue with a low voltage message.
First time it happened I turned on the car like normal made it around the corner and the car turned off completely, I tried to start it and it would turn over but not start completely until I pressed the gas at the same time, message appeared on dash saying LOW VOLTAGE
I thought it was the alternator even though I DID NOT have a charging system fault message, I went ahead and changed the alternator.
Even with the new alternator it happened a second time I started the car like normal and made it to the corner and same thing it turned off on me and displayed LOW VOLTAGE it started back up only as I stepped on the gas and had the revs high. I made it home and let the car idle to see if it would turn off but it did not.
Also possibly related since it recently started happening, ill insert the key (not start) and everything lights up normal but then all the lights just turn off as if no power, if I reset the key they come back on like normal.
In summary:
Car will start normal
Stalls out
turns over but won't start
LOW VOLTAGE
New alternator put in but same issues
I have a 2000 c5 and recently have been having an issue with a low voltage message.
First time it happened I turned on the car like normal made it around the corner and the car turned off completely, I tried to start it and it would turn over but not start completely until I pressed the gas at the same time, message appeared on dash saying LOW VOLTAGE
I thought it was the alternator even though I DID NOT have a charging system fault message, I went ahead and changed the alternator.
Even with the new alternator it happened a second time I started the car like normal and made it to the corner and same thing it turned off on me and displayed LOW VOLTAGE it started back up only as I stepped on the gas and had the revs high. I made it home and let the car idle to see if it would turn off but it did not.
Also possibly related since it recently started happening, ill insert the key (not start) and everything lights up normal but then all the lights just turn off as if no power, if I reset the key they come back on like normal.
In summary:
Car will start normal
Stalls out
turns over but won't start
LOW VOLTAGE
New alternator put in but same issues
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,659
Likes: 4,091
From: Cape Coral, Florida
Not a good idea to fire the “parts canon” without doing some diagnostics first...can get expensive !!...concerning the alternator it’s best to have your OEM alternator rebuilt instead of going to an aftermarket...there are some stickies on alternators in the Tech section up top...concerning your other concern it sounds like a bad ignition switch...select “voltage” on the DIC try turning the key on and see what the voltage reads...it will read about .5 volts lower than your battery...if your reading 7 or 8 volts instead of 12.6 of a fully charged battery cycle the key rapidly on and off a dozen times (to remove any surface oxidation on the switch contacts)and then check the voltage and try to start the car...when I had issues with my switch a few years back I was seeing 8 volts and I knew it was the switch...you can try that !!
Last edited by C5 Diag; Jan 6, 2021 at 08:09 AM.
Melting Slicks
Joined: Nov 2014
Posts: 3,399
Likes: 1,339
From: Havre de Grace Maryland
Also, if you have one, try a second key to see if you get the same result. I had start problems with mine several years ago. Cleaned my key and squirted CRC MAF Sensor Cleaner in the key hole and no more start problems. Now I do this 'ignition cleaning' at least 2 times a year. Hope it works for you.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
Likely suspects are the ignition switch or a bad battery connection. Check the connections for both battery cables at every end. Try rotating the "tight" battery ends to make sure they are tight and the bolts did not bottom out instead.
Advanced
Joined: Jan 2020
Posts: 79
Likes: 47
From: Los Angeles, CA
If you can see it, what's your battery voltage reading at? I don't have the 'low voltage' signal on my DIC but my battery voltage never exceeds 12.6V. I idle around 12.1-12.3V - had my battery inspected at Autozone yesterday and they said my battery is still good. I also suspect it could be the alternator but nothing confirmed right now.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,659
Likes: 4,091
From: Cape Coral, Florida
If you can see it, what's your battery voltage reading at? I don't have the 'low voltage' signal on my DIC but my battery voltage never exceeds 12.6V. I idle around 12.1-12.3V - had my battery inspected at Autozone yesterday and they said my battery is still good. I also suspect it could be the alternator but nothing confirmed right now.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,659
Likes: 4,091
From: Cape Coral, Florida
If you can see it, what's your battery voltage reading at? I don't have the 'low voltage' signal on my DIC but my battery voltage never exceeds 12.6V. I idle around 12.1-12.3V - had my battery inspected at Autozone yesterday and they said my battery is still good. I also suspect it could be the alternator but nothing confirmed right now.
Last edited by C5 Diag; Jan 7, 2021 at 10:22 AM.
Advanced
Joined: Jan 2020
Posts: 79
Likes: 47
From: Los Angeles, CA
I think when it becomes a bigger problem, I'll do more research before opening a new thread. I was curious if OP has a similar issue as mine, though right now my car still starts up without any issues... for now.
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Thread Starter
Cruising
Joined: Sep 2020
Posts: 11
Likes: 1
Not a good idea to fire the “parts canon” without doing some diagnostics first...can get expensive !!...concerning the alternator it’s best to have your OEM alternator rebuilt instead of going to an aftermarket...there are some stickies on alternators in the Tech section up top...concerning your other concern it sounds like a bad ignition switch...select “voltage” on the DIC try turning the key on and see what the voltage reads...it will read about .5 volts lower than your battery...if your reading 7 or 8 volts instead of 12.6 of a fully charged battery cycle the key rapidly on and off a dozen times (to remove any surface oxidation on the switch contacts)and then check the voltage and try to start the car...when I had issues with my switch a few years back I was seeing 8 volts and I knew it was the switch...you can try that !!
It was the switch thank you boss 👍
Thread Starter
Cruising
Joined: Sep 2020
Posts: 11
Likes: 1