I'm considering upgrading my alternator to fix my charging & low voltage problems. As far as "non-stock" current draw, I have a 550 watt amp, a Meziere electric water pump, & 2 in-tank fuel pumps. With that in mind, is a 200 amp alternator sufficient? I was considering Quick Start for $350: http://store.alternatorparts.com/gm.aspx

Any other suggested suppliers?

Thanks,
Bobby

 

Here's a bump for your post. I never knew you could buy a heavier amp alternator so this is good news to me. As long as they have a good warranty on them.

 

Are you sure the alternator is your problem?

What battery are you using?

I just stuck an ODESSSEY in mine after the OPTMA (red top) took a dump.

42 lbs!

12 year design life though and major ampacity.

 

Bobby,

Can you go into more detail on your charging & low voltage problem? Your water pump draws about 46 amps, do you know what the fuel pumps draw? The reasons for my questions, you would have a better chance of getting the right fix by figuring the load and when the load is at its highest. This could be measured with an amp meter while your car is in operation. Does the water pump run full time? Are the fuel pumps drawing a constant current or does it ramp up with fuel flow? What engine rpm’s do you have charging issues?

Eric D

 

Read the following threads. They describe how the PCM and the alternator are intertwined.

Note the fact that the PCM expects to see certain values and may set fault codes with a replacement alternator. (Especially the early C5’s)


Post #8
http://forums.corvetteforum.com/c5-g...lp-please.html


Post #5
http://forums.corvetteforum.com/c5-t...eck-first.html


Post #2
http://forums.corvetteforum.com/c5-t...diagnosis.html


http://forums.corvetteforum.com/c5-t...sket-swap.html

http://www.gearchatter.com/viewtopic10124.php

Good luck and keep us posted as to what your experence is with the upgrade.

 

Thanks everyone. Before I received all these suggestions yesterday, I had already ordered an new alternator from Nations:

http://www.nationsautoelectric.com/h...-corvette.html

I don't know the current draw yet. Not sure how I can check that while driving? Ideas?

As far as load, here are the extras: LARGE injectors 79lb/hr, electric H2O pump running full-time. 2 fuel pumps (I believe run full-time, but not sure). 550 Watt Amplifier that draws up to 50 AMPS (I believe this scales up with volume, so not necessarily full-time).

I don't know the battery off the top of my head, but it was a high amp model that I bought from Sam's Club (only about 3-4 mths old). I'm going to have to look into this light battery you mentioned!

Thanks for all the suggestions and posts. I have some more homework to do and will get back to y'all to let you know the update...

Thanks again!
Bobby

 

Bobby,

You never gave any details about problem you are having. If you have low voltage, how low and when?

 

Sam's Club has a great return policy on a battery, free exchange for 3 years with no pro rate, but it is for a reason. The quality of the battery is ???? but they hope you get a good one after the returns. You may have purchased a amped up battery model but this does not mean it is a quality battery. The MFG maybe good but Sam's can and does get things produced that are good but not great. Sooooo check the battery at Sears, Pep Boys, Auto Zone, and Advanced Auto with their free battery review for performance. You can return to Sam's if it does not match up.

 

The problem I have is that while driving around my voltage is usually 12-13 volts. If I have headlights on and turn a blinker on, you can see the voltage fluctuate to the beat of the blinker. Cool, huh? If the stereo is on and you get a bass note, the headlights dim.

The worst part is if I stop the car to tweak my tune and re-start several times, the voltage drops down below 11. When I get below 11 volts, it is hell getting the car started. It just doesn't seem that the battery has a chance to get fully charged while driving because all the accessories are draining the system. If I want to do multiple restarts, I usually hook up a battery charger to keep a charge going.

Part of the problem is that the water pump runs when the key is ON but the motor is not running (i.e. the key position for uploading a tune file). We did this on purpose because I was having heat soak issues and at times I need to keep the water pumping when the car is turned off. Hopefully this helps characterize the situation a bit better.

Thanks, Bobby

 

did you upgrade the big 3?

 

What's the big 3??

 

it's where you upgrade the wiring from the alternator to the battery, the battery negative to the chassis and the chassis to the engine block. (or battery neg to block)

this thread shows how to do it on a c5.

http://forums.corvetteforum.com/audi...ig-3-pics.html

this thread explains why to do it:

http://www.the12volt.com/installbay/...TID~73496~PN~1

doing this upgrade should help some of your issues with low voltage and cost a lot less than a new alternator.

 

Great suggestions - thank you.

 

A manual kill switch on the water pump will give you options you don't have now. Easy to do too.

 

Bobby

I added this to the BIG THREE post Check it out. It might help you solve your issue:


DPG

I hope you don't mind me adding this to your fantastic post!

I've been thinking about making this post for a while. Its raining and cold out and my ZO6 is beyond dead so, I'm bummed out.

If you improve the following MAJOR wiring paths, you will significantly improve the electrical system operation and efficiency!! Ive been studying this issue for a LONG TIME and here are my recommendation:

1- Follow this post and clean and tune up your IGNITION SWITCH. Its FREE and works very well!! Over a period of time the contacts inside the switch get burnt and some critical body control and PCM circuits receive less than actual battery voltage. Once you clean the ignition switch and improve the contact pressure on the switches, you will see a significant improvement in module functionality:

http://forums.corvetteforum.com/c5-t...ch-repair.html


2- Improve the battery to alternator circuit. The alternator charges the battery thru the starter solenoid. In that circuit there are in line fuseaible links and eyelet type connections that are exposed to heat, weather and corrosion. As time goes by, these connections become POOR and alternator performance suffers. Examine the attached GM Schematic and notice how the alternator connects to the battery and the fusible links on the starter solenoid for the alternator.
-----------------------------------------------------------------



--------------------------------------------------------------------

Recommendation! Run a 4 - 8 gage wire from the POSITIVE battery terminal to the field terminal on the back of the alternator. Obtain a 60 amp fuse and fuse holder and install a fuse in that line near the battery to protect that hot wire from short circuits.

3- Better Chassis Ground at G-104/108. Chassis ground G-104/108 is a significant grounding point for numerous other chassis grounded circuits. ALL of the other chassis ground points enter the negative battery terminal through this wire.



Remove the negative battery terminal and remove the plastic/rubber cover from the battery terminal. You will see that the wire connections to the neg terminal are CRIMPED to the wire. This crimped connection frequently gets corroded/burnt/loose etc.. and causes poor performance. Remove the small negative ground wire from that connection and replace it with a 4 -8 gage wire. When you get the wire in the crimp connection, solder the connection. I use a giant soldering gun or a torch on low flame. Use lots of non acid flux for a good clean solder joint.

While your examining the battery terminals, inspect the POSITIVE BATTERY terminal wire crimped connections for proper conditions.

MAKE SURE THAT YOU PROPERLY ATTACH THE BATTERY TERMINALS TO THE BATTERY!! They need to be clean and tight. The GM torque spec for 97-2003 battery terminals is 11 ft/lbs.

If you follow the POSITIVE battery wires out of the crimped connection on the battery lead, you will see that it goes to TWO places:

- The Starter (main starter wire)
- The Engine Compartment Fuse Block, B+ terminal (main power for ALL the under-hood loads)


If you look at the pic below, you will see that the under hood fuse center has a B+ terminal on it that is where the battery cable connects to power the fuse block. You will also notice that theres a SECOND wire on that terminal. That wire is the B+ power wire for the Instrument Panel Fuse Block. NOTE! You will also note that in my pic, theres a "THIRD" connection. Thats my heated seat power line. You will NOT have this wire on yours



Some people have improved instrument panel circuit operation by incorporating that feed wire directly to the battery terminal; either in the crimp connection or if you have a side and top terminal on your battery, on one of those terminals.

General Chassis Grounds and circuit performance. Over the years, I have seen too many electrical problems to count. Many problems that I have seen can be contributed to poor chassis grounds. I have covered this in many electrical post but, make sure that you inspect and maintain your chassis grounds. Heres are some well documented examples of what hiding at your ground and grounding points!









THE GROUND SCHEMATIC!




The BIG THREE really does help. Get that engine and alternator better grounded to the CHASSIS!!!!


I hope this helps the BIG THREE get some more exposure and to help those of you who are experiencing POWER issue solve them. I will also copy this into my sticky (IMPORTANT ELECTRICAL INFORMATION (Long)

Bill Curlee

 

Also, even though it is common sense, make sure your battery is charged completely. With the electrical problems these cars can have, a weak battery will exaggerate other problems as well

 

Thanks again guys! I really appreciate all the time and thought everyone has contributed. As soon as I get my taxes done, I will have some time to do all my homework assignments you all recommended! I will update you as soon as I get to work on it. Might be after Tuesday at the rate I'm going...

Thanks, Bobby