My car's battery keeps draining overnight.

[derek2079]

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]

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.

 

[MustangIIMatt]

You, or your mechanic, should perform a parasitic draw test:


View: https://m.youtube.com/watch?v=KF1gijj03_0

 

[wicked93gs]

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

 

[MustangIIMatt]

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

That's literally what the video I posted shows.

 

[southcross2631]

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]

Turns out it was just a bad battery. Replaced. No issues right now.

 

[southcross2631]

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]

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.

Boy do I fit that description!!!!
I have three tool boxes and I'm still not a mechanic!!!!

 

[Olivethefet]

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.

 

[MustangIIMatt]

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.

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.)

 

[Olivethefet]

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