Car Knowing Stuff Type Guys.......

My Mustang has 'lectercal issues.

I plan to take it in, and have a mechanic go through it to find out exactly what my problem is.  (I'm pretty sure I have a short somewhere, that is constantly draining the battery.)  I charge it up, or jump it, every thing is fine, but when it sits over night (even after running all day) deader than a hammer.  New alternator last year, and new cables.

So I guess here is my question. 

A.  Do I buy a new battery?  I ask, because I don't want to sink the 80 bones, if the guy finds the problem, and it's an easy fix.  I have no idea of the age of the battrie, but it looks "fairly" new, and is clean.

B.  The reason I ask, is because I have heard that if you have a batterary run down dead too many times, you can essentially  "kill" it.  Is this a myth?  Could it be that I simply have a ruined battery, and potentially no "drain" at all?


Muchos Garcias.

I wish.  It's been more like SLC.

Dude, take your battery to Checker and they'll test it for you. A brand new battery can go dead and lose its capacity after several weeks if you don't run the engine during that time.

You should hook up a multi-meter to see if your alternator is charging when your car is running.(there should be around 14.7 volts after the battery has been somewhat recharged...higher voltage, over a longer time means the alternator is working, but the battery is not accepting the charge)   Put your battery on a charger, and see if it will take and hold a complete charge before replacing also. 

Alternatively, hook a multi-meter to the battery after running the vehicle for awhile, and see if battery voltage is dropping significantly, if it is, there is either something draining it, or there is short somewhere, or your battery is shot.

Buy a battery before aggravating your friend the mechanic with something that's fairly obvious.

The clue here is that the car is 'Fine' if it's running off the alternator. The alternator will maintain a battery, but it won't recharge one, and only God can bring one back to life that loses it's cranking amperage from sitting overnight.

Soooo, the alternator is fine (checking it won't hurt, but I'd guess the $7.03 for 22 hours a week kid at Checkers has no more idea how to check it than you do), and the battery is probably toast.

If the voltmeter hooked to the battery reads anything under 8.5 with the car off, it's done for sure, and anything under 10 and over 4 or 5 years old probably is too.

Awesome.  Thank you.

 

Should have put that in the OP.  '67, 289.  No AC.  Can't remember the name of the battery, but it's def. not original.

Yeah, I thought 80 is a little steep too, but I was guessing high.

The alternator is new from last year(by me.  My first attempt to "fix" what was wrong.  Next was new cables.  Still nothing.)

I'll buy a new battery.


[small disclosure] Would sparks flying out from under the horn bezel when it's pressed, have any contribution to global problem? 


Joe Gibbs Racing!

I always wanted a Mustang