tttrex

it'll be fine for hours at a time. then it'll say "low voltage, reduced power" and all of the gauges will drop to zero. but it runs perfect while all of this is going on.... any thoughts?

04zjimc

Sounds like your battery may need replacement...how old is it?

tttrex

little over a year old. it's a cheap duralast battery.
this is my 1st corvette, are they sensitive to wimpy batteries?
I actually got it at a crazy cheap price because the guy couldn't figure it out.
he replaced the alternator and the "main computer" he said. but still the same problems.

Jeff T.

Personally I don't know of a car that is more sensitive to a low battery than the C5. Second thought, just because the battery is new doesn't mean it's fully charged.

Rico7142

Low batttery causes all sorts of problems in these cars

tttrex

I had the battery on a charger all day and just connected it a lil while ago and same thing.I put a volt meter on it before putting it back in and it read 13.99v... I put it in and started the car and put the meter back on, it read 25v !! It seems to be getting worse, last week all I had to do was disconnect and reconnect the batt and all was ok for a while. but now it's not going away. I've read on here about the ground wire under the battery, checked it out and its getting good contact.
maybe a higher CCA battery would help.....

JR-01

Start with making sure battery is 100% charged and make sure all connections are clean and tight..

tttrex

all main connections? terminals, starter and such?
or everything? lil wires like radio?
forgot to mention that my ac turns on by itself and seems to have a huge draw on the engine.

JR-01

Battery terminals first. Have you done any mods to the car? Aftermarket parts?

tttrex

the only obvious possible upgrade is a bola exhaust, which may be stock in these cars for all I know. otherwise, it looks stock.

tttrex

even though the battery reads a full charge, is it possible that it just can't handle all of the electronics in this car?
I run an optima red in my jeep and it spins the hell outa that lil engine.... maybe a red top will help the vette?

tttrex

got it.
most expensive battery I can find..... genius.
consider it done.

new to vettes, new to this site.... so far both have stupid issues.(issues.. people...
same difference)

thank the rest of you for trying to help.

Slo Yelo C5

Do you know how to check the codes? If not, search for the video of checking codes on a C5 (can somebody post this video if possible?). That's the best place to start. It should at least provide a starting point (assuming it's generating codes). If you know how to check them, start posting the codes your car is throwing.

Jeff T.

Watch the attached video, pull the codes and post them.

bikeriderga

Everyone telling you pull the codes first are correct.
The only way you can properly diagnose electrical problems like this is to first consult the CAN bus. That does not mean it will find the actual problem, but it prevents you from going to a massively expensive process of parts elimination.

If there are no codes showing up, then look at battery, grounds, or loose/frayed wires. Normally, loose wires, faulty grounds, etc. will throw codes as well, but not always using OBD2 type diagnostics (aka PID codes).

JR-01

I would suggest making sure battery is fully charged and terminals tight first. A weak battery can throw a lot of codes that could lead you on a wild goose chase. When you know you have a good battery at 100% charge, then pull the codes. Just my opinion.

narlee

A reading of 25 VOLTS would point me in the direction of the charging system.

98C5P

Replaced the alternator with incorrect one?
or did he have OEM one rebuilt?

https://www.corvetteforum.com/forums...nd-issues.html

friou

First thing, and I say this with all due respect, THERE IS NO SUCH THING AS A STUPID QUESTION! No one is born with built in knowledge and everyone has to start somewhere. Yes, C5's are incredibly sensitive to battery/voltage issues. I had my go around with that and discovered my next to brand new battery was defective from the factory. Get it checked and as advised above check terminals and connections. Regarding the alternator replacement, I've been advised that if you have an issue with your alternator, get the orginal rebuilt, don't buy a unit out of the auto parts store, will also cause problems. No personal experience on that but have seen this mentioned a number of times on this forum. Good luck!

GCG

25v is alarming! How did you measure this?