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My car's battery keeps draining overnight.

  • Thread starter Thread starter derek2079
  • Start date Start date Feb 22, 2020

derek2079

Member
Jan 21, 2020
34
8
18
Salt Lake City, Utah
Feb 22, 2020
#1
  • Feb 22, 2020
  • #1
I took my 67 mustang to auto zone to have my battery tested because it kept draining overnight and I also took it to a mechanic who said my wiring harness was messed up. I have a new alternator, new starter, basically complete engine rebuild along with transmission rebuild. I'm going to have to take it to a mechanic and pray on my lucky stars he can fix it. If anyone here has any idea's of what it could be so I could run it by the mechanic please let me know because it may help out especially if you are a mechanic or have expert advice.
 

derek2079

Member
Jan 21, 2020
34
8
18
Salt Lake City, Utah
Feb 23, 2020
#2
  • Feb 23, 2020
  • #2
After some research I'm beginning to think it's the voltage regulator. Going to buy one and see if it does the trick, unless anyone else has anything else I should try.
 

Adieu

Easy there, this ain't a dating site.
20+ Year Stangneter
Mar 7, 2002
9,531
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224
Feb 23, 2020
#3
  • Feb 23, 2020
  • #3
You, or your mechanic, should perform a parasitic draw test:

View: https://m.youtube.com/watch?v=KF1gijj03_0
 
Reactions: Realmongo, Olivethefet and kiddiccarus

wicked93gs

15 Year Member
Sep 30, 2006
1,198
228
93
Nashville TN
Feb 24, 2020
#4
  • Feb 24, 2020
  • #4
You can test which circuit has the drain by removing one fuse at a time...though that only powers interior circuits really. You can always test each and every positive wire though to find out which ones are active with the ignition off...will narrow down possibilities
 

Adieu

Easy there, this ain't a dating site.
20+ Year Stangneter
Mar 7, 2002
9,531
5,187
224
Feb 24, 2020
#5
  • Feb 24, 2020
  • #5
wicked93gs said:
You can test which circuit has the drain by removing one fuse at a time...though that only powers interior circuits really. You can always test each and every positive wire though to find out which ones are active with the ignition off...will narrow down possibilities
Click to expand...
That's literally what the video I posted shows.
 
S

southcross2631

Active Member
Dec 13, 2019
73
76
28
Athens,Tn
Mar 28, 2020
#6
  • Mar 28, 2020
  • #6
Unhook your negative battery cable clamp a test light to the cable and stick the probe into the negative terminal if it lights up you have a draw.
Start unplugging things until the light goes out. Then trace that system. Don't forget to unhook the dome light or you will be chasing your tail.
 

derek2079

Member
Jan 21, 2020
34
8
18
Salt Lake City, Utah
Mar 31, 2020
#7
  • Mar 31, 2020
  • #7
Turns out it was just a bad battery. Replaced. No issues right now.
 
Reactions: Olivethefet
S

southcross2631

Active Member
Dec 13, 2019
73
76
28
Athens,Tn
Apr 1, 2020
#8
  • Apr 1, 2020
  • #8
That's the problem with taking it to one of the chain stores they do not know enough to check it twice . Once to take off the surface charge and the second time to check the reserve of the battery. I would find a new mechanic. He should be working at Autozone and not be working on cars. Just because you buy a tool box does not make you a mechanic.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,926
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203
polk county florida
Apr 1, 2020
#9
  • Apr 1, 2020
  • #9
southcross2631 said:
That's the problem with taking it to one of the chain stores they do not know enough to check it twice . Once to take off the surface charge and the second time to check the reserve of the battery. I would find a new mechanic. He should be working at Autozone and not be working on cars. Just because you buy a tool box does not make you a mechanic.
Click to expand...
Boy do I fit that description!!!!
I have three tool boxes and I'm still not a mechanic!!!!
 

Olivethefet

I will own your nuts! LOL
5 Year Member
May 17, 2018
2,596
1,790
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Enterprise AL
Apr 8, 2020
#10
  • Apr 8, 2020
  • #10
I have a greasy hat and a shirt with my name on it, own three toolboxes, and changed a tire once! I am a mechanical god!

Oh wait. I cant even put on a stupid timing chain cover without it leaking. I'm the worst mechanic ever.
 

Adieu

Easy there, this ain't a dating site.
20+ Year Stangneter
Mar 7, 2002
9,531
5,187
224
Apr 8, 2020
#11
  • Apr 8, 2020
  • #11
Olivethefet said:
I have a greasy hat and a shirt with my name on it, own three toolboxes, and changed a tire once! I am a mechanical god!

Oh wait. I cant even put on a stupid timing chain cover without it leaking. I'm the worst mechanic ever.
Click to expand...
Three toolboxes?

Peasant.

Truth be told, Ford 302 timing covers are kind of a pain in the ass to seal. Everyone else's small-block V8 was a lot easier. I'm ASE Certified in engine repair, and ElSuperPinto's timing cover is leaking right now. (The BMW N20 engine I did that insanely convoluted valve cover on today, however, is tight as a ing drum.)
 
Reactions: General karthief

Olivethefet

I will own your nuts! LOL
5 Year Member
May 17, 2018
2,596
1,790
143
Enterprise AL
Apr 8, 2020
#12
  • Apr 8, 2020
  • #12
I'm joking and not really knocking anybody. That's why I ended it with I suck. I really only have 2 toolboxes. Hopefully the cover is sealed on my car. If it's not please come help me! Cuz I suck. Lol
 
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