C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

Help with chasing battery drain

Thread Tools
 
Search this Thread
 
Old Mar 12, 2016 | 12:18 PM
  #1  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default Help with chasing battery drain

I have a parasitic drain, or am in the process of determining if I do, on my 2000 MN6. No codes. New battery, 12.75 V,
hood light disconnected.

Okay, I have my amp meter set up in line with my negative terminal and the ground cable. I currently read 1.206 amps. Following one of Bill Curlee's old posts, from what I understand I have to wait 10 - 15 minutes for the car to go to sleep. Is that correct? Also, he said that every time you pull a fuse, it wakes the car back up, so you have to wait another 10 - 15 minutes. Can I leave the door open? Won't the car go to sleep with the door open? I realize my target is between 20 and 30 ma.
With the battery disconnected and using the jump wires connected to the amp meter, is there still enough current to wake the car up?

Mike

Last edited by SoAlVette; Mar 12, 2016 at 12:27 PM.
Reply
Old Mar 12, 2016 | 12:37 PM
  #2  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

I waited 20 minutes, still reads 1.206 amps. I opened the door, the draw did not change, does that mean that my car is not going to sleep? Am I doing something wrong? When I opened the door, my interior lights did not come on.
Reply
Old Mar 12, 2016 | 01:15 PM
  #3  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

Disconnected the main red wire to the alternator and checked amperage between the cable and the terminal. Read 0.00. Is that the correct way to test for bad diodes?
Reply
Old Mar 12, 2016 | 01:58 PM
  #4  
dadaroo's Avatar
dadaroo
Le Mans Master
 
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Default

Not enough info on what you measured and where. If you measured from the battery to the alternator it may not mean anything.


Mr. Sam
Reply
Old Mar 12, 2016 | 02:55 PM
  #5  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

When you INSERT the amp meter between the NEG batt terminal and the cable, you SHOULD see a rather large current spike.. Mine usually goes to approx. 8 amps. It then falls off in 2-3 small steps down to minimum draw.

YES,, you can leave the door open and when it goes to sleep, just pulling a fuse shouldn't wake it up. IF you insert it back in the slot, it may depending on what the load is, wake up.

If you measure between BATT terminal and the red wire on the back of the ALT, you should see ZERO amps
Reply
Old Mar 12, 2016 | 03:20 PM
  #6  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

Okay, I'm doing something wrong. I do not get a spike. I am still getting a reading of 1.206 to 1.211, which is too high if it is asleep. I would like to try to isolate the engine fuse box to eliminate one or the other. Tried disconnecting the red wire on the engine fuse box stud(there are 2, a red and a black), still get the same readings.
Does that mean my problem is coming from the engine fuse box?

On the alternator, I disconnected the main red wire(to the battery}, and tested from it to where it was connected on the alternator. The negative battery cable was disconnected. Should the battery have been hooked up?

Last edited by SoAlVette; Mar 12, 2016 at 03:22 PM.
Reply
Old Mar 12, 2016 | 03:36 PM
  #7  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

Originally Posted by SoAlVette
Okay, I'm doing something wrong. I do not get a spike. I am still getting a reading of 1.206 to 1.211, which is too high if it is asleep. I would like to try to isolate the engine fuse box to eliminate one or the other. Tried disconnecting the red wire on the engine fuse box stud(there are 2, a red and a black), still get the same readings.
Does that mean my problem is coming from the engine fuse box?

On the alternator, I disconnected the main red wire(to the battery}, and tested from it to where it was connected on the alternator. The negative battery cable was disconnected. Should the battery have been hooked up?
There SHOULD ONLY BE TWO WIRES on the eng fuse box power stud. One RED WIRE from the BATTERY and one RED WIRE that gets power from that battery wire to feed the PASSENGER FUSE BOX. That's IT!

YES,, When you read alternator AMPS, the battery MUST be connected. How can it read amps with out power..

Bill
Reply
Old Mar 12, 2016 | 03:43 PM
  #8  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

Heres what mine looks like YEA YEA,,,,, I know,,,,, mine has three wires.

The NON OEM wire on mine is the fused power feed to my heated seats that I installed.

Yours SHOULD only have the TWO RED wires:


Last edited by Bill Curlee; Mar 12, 2016 at 03:45 PM.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Mar 12, 2016 | 04:05 PM
  #9  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

Here is what mine looks like, I have the CAGS skip as well. It is on red, one black.



Also, I just connected the battery and tested the alternator again, this is what I got. Is this my problem?

Reply
Old Mar 12, 2016 | 04:10 PM
  #10  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

You should have ZERO amps on that alternator reading! WELL,,,,,,,,,,,,,,,,Theres your issue!

With the alternator disconnected, what is the battery current draw reading???

I bet it goes to sleep and in the normal range!!
Reply
Old Mar 12, 2016 | 05:03 PM
  #11  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

I've read some posts on here where members have had trouble buying aftermarket alternators for the C5's. Is it better to have this one rebuilt, or is there a specific make/model alternator that will not give me any issues?
Reply
Old Mar 12, 2016 | 06:08 PM
  #12  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

If it were me,,,,,,,,,,,,,,,,,,, I would have mine rebuilt by a good shop.

Bill
Reply
Old Mar 12, 2016 | 08:37 PM
  #13  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

Well, I tried getting a reading of amp draw with the alternator disconnected, and i am still getting 1.209. Now I really don't understand. If the alternator is drawing 1.112, with it disconnected the draw at the battery should have gone down, but it did not. thoughts?

Last edited by SoAlVette; Mar 12, 2016 at 08:39 PM.
Reply
Old Mar 12, 2016 | 09:25 PM
  #14  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

Looking at my picture in post 9 showing my engine fuse box, is the red wire the one feeding the inside fuse box, or the black wire. Still would like to isolate the boxes since the alternator may not be the only point of my drain
Reply
Old Mar 12, 2016 | 10:00 PM
  #15  
GCG's Avatar
GCG
Melting Slicks
10 Year Member
 
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Default

Originally Posted by SoAlVette
Looking at my picture in post 9 showing my engine fuse box, is the red wire the one feeding the inside fuse box, or the black wire. Still would like to isolate the boxes since the alternator may not be the only point of my drain
Mine are both red, but it is easy enough to know which one is the one that goes to the inside fuse box:
One goes from the stud to the battery. The other one is the one that goes inside
Reply
Old Mar 12, 2016 | 10:18 PM
  #16  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

So, if I disconnected the one that goes to the battery and was still getting draw on the battery, then it was neither of the fuse boxes, and takes me back to the alternator, if it was the line going to the inside box, could still be the engine box. If I disconnect both wires, that disconnects both fuse boxes, correct?
Reply
Old Mar 12, 2016 | 10:22 PM
  #17  
GCG's Avatar
GCG
Melting Slicks
10 Year Member
 
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Default

Originally Posted by SoAlVette
Well, I tried getting a reading of amp draw with the alternator disconnected, and i am still getting 1.209. Now I really don't understand. If the alternator is drawing 1.112, with it disconnected the draw at the battery should have gone down, but it did not. thoughts?
There's something wrong here. If the total draw is 1.2A and the alternator is responsible for 1.1A, there should only remain 0.1A with the alternator disconnected if nothing else has changed...
It might be a good idea to reconnect everything and do this all over again.
Reply

Get notified of new replies

To Help with chasing battery drain

Old Mar 12, 2016 | 10:32 PM
  #18  
SoAlVette's Avatar
SoAlVette
Thread Starter
Racer
10 Year Member
 
Joined: Jan 2013
Posts: 415
Likes: 19
From: Mobile Alabama
Default

That is what I was hoping, I can get the alt rebuilt, but is that the problem? Tomorrow I will start all over and post my results.
Reply
Old Mar 12, 2016 | 10:32 PM
  #19  
GCG's Avatar
GCG
Melting Slicks
10 Year Member
 
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Default

Originally Posted by SoAlVette
So, if I disconnected the one that goes to the battery and was still getting draw on the battery, then it was neither of the fuse boxes, and takes me back to the alternator...
Yes, or the starter or the linking cables. Remember that the battery is linked to the alternator via the starter.

Originally Posted by SoAlVette
...if it was the line going to the inside box, could still be the engine box...
No, it should be the inside box or downstream from it.

Originally Posted by SoAlVette
...If I disconnect both wires, that disconnects both fuse boxes, correct?
Yes, but to do that is enough to disconnect just the cable between the battery and the stud, like we discussed above.
Reply
Old Mar 12, 2016 | 10:36 PM
  #20  
GCG's Avatar
GCG
Melting Slicks
10 Year Member
 
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Default

Originally Posted by SoAlVette
That is what I was hoping, I can get the alt rebuilt, but is that the problem? Tomorrow I will start all over and post my results.
I wouldn't jump the gun until everything is crystal clear, with no conflicting readings.

Last edited by GCG; Mar 12, 2016 at 10:37 PM.
Reply



All times are GMT -4. The time now is 01:48 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE