Ok. From the beginning.

2001 Base C5- 64K Miles. Extremely well kept up car.

Battery is New. Volts- 12.5

Noticed my Traction control, active handling and abs scrolling across the DIC. Battery volts were a little low. 11.8.

Charged battery overnight. Volts back to 12.5. Ran it in the driveway for about 20 minutes with headlights on bright, AC and radio on. Volts slowly dropped down to 11.9. Had original 110 Amp Valeo alternator checked. Tested Bad.

Installed new 145 Amp alternator. Howling very loudly from start. Within 5 minutes running in the driveway with the hood open the new alternator was howling BAD. Alt case was hot enough to fry spit.

Returned 145 alt. and purchase 110 Alt. Matches Original exactly. Within 5 minutes idling in the driveway it fries spit also. Output per meter shows only 12.2 volts on back of alt. Removing the battery wire from alt and post on back of alt reads 18.2 volts.

Done so far:

Fairly mechanically inclined. By no means a full blown mechanic but I did build my first two cars from frame up.

Battery lead from alt to battery shows 0 ohms.

Removed and cleaned all grounds on front half of car. And to be honest, this wasn't needed. They were all pristine on all contact surfaces. Put dielectric grease on them all and re-installed. Changed both battery terminals. These were also near pristine. Very light oxidation on them.

Removed wires, big red, little orange and little grey from starter solenoid and cleaned very well with sandpaper. These were also near pristine and torqued well when I removed them. Dielectric grease on these also and torque back. Starter and solenoid looked fine.

No Codes. I cleared them, which had a few in history when I bought the car in December, and no new codes are coming up. Totally clear.

When I re-install the old alternator, no howling and no overheating it just doesn't charge very well but does charge better than both new alternators do.

Where do I go from here?

Thanks in Advance.

 

Bad belt tensioner? BTW, when you say the new alternator is an exact match, do you mean physically or by p/n?

 

Are you buying somewhere like Orileys or Auto Zone. They sell garbage. Go to Napa or an independent rebuilder to get a good one. The high volume rebuilders that supply the air freshener type auto parts stores use junk parts. Changing to a 145 will have no ill effects.

 

Belts and tensioner and basically everything on the front of the motor have less than 3k on them. Changed evrything when I did the balancer.

Physically it is the same but not the original Valeo.

New symptom. With engine off and ignition switch on a volts on battery dropping even with a good 10 amp charger connected. Ignition relay pretty hot to the touch. Pulled ignition relay and the volts on battery come up to 12.6 in about 5 minutes. Somerhing has more than a 10 amp draw with switch on. All accessories are off. Only interior lights on for this test.

Ignition switch? Starter?

 

Both "new" alts. are cheap remans. All that is available in the area and they both had to be ordered. The stealership didn't even have one. Both that I put on performed exactly the same. Not saying I couldn't have gotten 2 bad ones back to back but it's doubtful.

Just trying to find something to work for 2-3 weeks as I have DC power building me a $700 HO alternator now.

 

They are all bad. Cheap bearings and electronic parts do not work.

 

My truck came with a 110 amp and I replaced it with a 145. I needed more to charge my trailer batteries. The truck was new at the time. I got it from Napa. The truck has almost 200,000 miles and it still works. I still have the new 110 around here some where. I saved it for our other cars but as of yet have not needed it. The one I bought from Napa was new not reman. About the same price there and no core so I could keep my new old one.

 

Put old alternator back in and it does charge better than both new ones. It heats up pretty good also though. Car running for about 5 minutes and the ignition relay gets pretty hot. Is this normal? Not "burn you" hot, but pretty warm for a plastic covered relay.

 

you can either rebuild your old alternator at an alternator / starter store

or

order the parts you need here

http://www.aspwholesale.com/index.php?

or

buy a remy 13381 which is a delco 110a alternator for the 6spd

or

there is a 150a ac delco 6spd alternator as well but i can't remember the part number

the remy is roughly $200 and the 150a is $250, with core both are less, rock auto sells both

 

4 speed auto. Pretty sure its a different unit.

 

I got my alternator from here:

http://fastlanepartssupply.com

A "New" battery should measure over 13 volts (13.6) and charge voltage will be over 14 (14.2-14.6)

I think you have a bad battery.

 

ah, you have an auto,

that would be ac delco 334-1399 for the 110a

or 334-1493 for the 150a

both those are ac delco part numbers. the 110a sells for roughly $200 most places

amazon often has good deals on ac delco

 

Sorry didn't notice I hit 12.5. Both a new diehard and a new redtop at 13.5 v.

 

meaning a new battery made the alternator work correctly? if so you found your problem

dead batteries, like REALLY dead, old batteries won't pull power from the alt

 

No. Meaning the above issues are happening with two brand new batteries. Diehard 13.62 and redtop 13.59 to be exact.

With either installed even with original alternator showing it is putting out 14.21 the batteries will both run down to 11.9 within 20 minutes idling in the driveway with no accessories on.

Damndest thing I've ever seen. But it is a corvette...

I used to be pretty big on the car stereo scene. I have been through way more than my share of charging issues and remedies. This has me stumped.

 

No he meant he hit 2 instead of 3. So he meant to type 13.5 not 12.5.

 

what the hell.,.

i have never heard of such a thing either.

all you can do is troubleshoot one thing at a time

 

Sounds like you need to monitor current and start unplugging fuses.

Could be your fuel pump.

Also, you do know that the grounds in these are crap.

 

That was my next thought...was just hoping someone else had similar experience.

Yes, what they call "grounds" are pretty much a joke. But as I said, when I removed each one they appeared as clean as if it had just left the factory.

Thanks for all of the replies and keep 'em coming please.

 

Maybe this thread will help you. Good luck.
http://forums.corvetteforum.com/c5-t...ing-issue.html