Charging System Questions

vector1 · #1 (**permalink**) 03-21-2009, 12:10 PM

sounds like the alt. is not actually putting the charge into the battery and the car is running off the battery and draining it then will not restart.

after the cobra is started put a voltmeter on the battery terminals and verify at least 13 volts, or after starting remove one of the posts, there is a preferred one, don't remember, and see if the car still runs, should if it is not efi.

RICK LAKE · #2 (**permalink**) 03-21-2009, 03:30 PM

zzmac I have heard more than once about these optima batterys having internal shorts on 1 cell and killing the Alt diodes in the regulator. 13.5+ volts is not enough to running all your systems and and charge the battery. It sound like only 1 of the 3 legs in the alt is still working. Are you sure that the Alt belt is not slipping on the pulley? The belt is not glazed? You have no charging after your short road test. As far as trying to start the car with another battery, what is the voltage on that battery? 12.5 or high would mean you have a good battery but you could also have low CCA cold cranking amps. How many grounds are on the car? How many go from the frame of the car to the battery? Where is the battery located. I would remove, clean the mounting area to the grounds and reinstall. If you strip the contection, this will cause the same problem. With everything hooked up, can you twist the battery connections? If yes, this is a problem. If not, go to the batery cable other ends and test and clean them. Do you have under driven pulleys on the motor? If all checks out, Do the Pepboys or Autozone thing. May sure you go to 2 different places. I believe your battery shorted and cooked the Alt. Road test your car with your volt meter hooked to the battery and have someone hold it or tape it to the windshield for this test. If you see the voltage fall with the mustang battery, the Alt is cooked. Rick L.

Blas · #3 (**permalink**) 03-21-2009, 05:45 PM

I thought he said 14+ volts off the alternator???

zzmac · #4 (**permalink**) 03-21-2009, 11:56 PM

Hey Blas, I want to thank you for all your help. You are definitely the best!! I didn't believe Rick so he comes a close second!!

Took my Optima battery, my old Autolite Ford Battery and my alternator to an auto electric place today and here's the results . :-)

The alternator tested like a champ!

The Optima battery out of the cobra tested as toast (with no butter).

The old Autolite battery out of the mustang tested as crap too but me and the tester (the tester and I, duh) agreed that it had a chance to recover. Got home and the Mustang battery started the car. (hello)

And I put a Napa battery with the same specs as the Optima (at half the price) in the cobra. Took it for a run (which is the whole idea behind a repair) and got home, shut it off, and then tried it again and it started right away! Holy Snikeees!

I read more than 1 bad review about the Optima so Napa it is. Thanks everyone, especially Blas and Rick.

Cheers!

RICK LAKE · #5 (**permalink**) 03-22-2009, 04:03 AM

zzmac I didn't ask you how old the mustang battery was or the CCA of it. As Far as the battery tests, the out come on the mustang battery was 12.4-12.6 and needs a charge? What was the CCA load. If this battery is 3-6 years old, it is getting to the end of the party depending on how many months it's rated. As far as the Alt and charging, Put a 1 hour cruise on it and then tell me it's OK. There is no 100% test for either of these parts. Gald the car is starting quick, keep an eye on the charging now. Good luck. Keep jumper cable in the trunk just in case.

Rick L. Ps no faith in me, must be a SPF thing. LOL

Blas · #6 (**permalink**) 03-22-2009, 05:27 AM

Here on CC - It's always a team effort getting these problems resolved...

zzmac · #7 (**permalink**) 03-22-2009, 08:01 AM

Rick, you're the best! And thanks for the suggestion of a 1 hour cruise. Going to do that and don't care if the car starts after that, just want to cruise for an hour. lol