Help, still not charging to full potential
 

Hi guys,

I recently posted about the car not charging even up to 12 volts.

Well, I figured out that problem (i think) and it was the battery terminal. I had changed it to one of those ones that you clamp the wire on instead of crimping it, like OEM style.

Well, not it will charge at around 12.5 volts, but that's still not what it is supposed to be at, 13+ volts when running.

I've added a few more ground wires to the engine bay as well as one to the interior of the car.

I've only added an aftermarket alarm and aftermarket car stereo (just the deck, no subwoofer) and even so, the stereo is not hooked up right now (it's not even physically plugged in to the back of it the deck) and it's STILL only charging at 12 volts-ish.

What do you think the problem is? The battery now?

I've replaced the battery when the terminal was the problem and it didn't do anything, but I am thinking that since the terminal had a bad connection (not because I didn't clamp it on right, it is just a poor design) that it might've ruined the battery's ability to charge correctly. The car will be at around 9 volts when I start the car until I step on the gas at 3k or when the cold idle kicks in, then it jumps to 12.5 volts.

Any thoughts? I am thinking maybe I should change to a deep cycle battery like the Optima batteries because it will hold a charge longer and better than the OEM type should.

You need to have your alternator tested. Pull it and have an auto parts store test it. When the car is running, the battery has little to do with anything. Proper alternator output would be at 14+ volts.

Like 88 stated get the Alternator tested.

Also a battery that falls below 10.2 volts when cranking is defective, not fully charged or on it's way out or the starter is drawing excessive amperage, or the gauge is not reading correctly.

Have both tested to be on the safe side.

sorry for slow reply,

but i have already had the alternator tested.

i've already had the alternator replaced twice. first with a rebuilt one from autozone (the only kind they sell is rebuilt ones, but it looks very nice and is passed off as new) and again from another one from autozone, again with another rebuilt one.

the symptoms are still there. still not charging to full potential when i start using the AC or rolling up the windows. after the car sits there for a day or so without moving it, it will crank and start up at 13 ish volts, then slowly goes back down to 12 volts.

again, i've already had the alternator tested and replaced, so i have no idea what the problem is, still.

Have you tested the output voltage created by the alternator? Takes less than one minute to do. As far as the quality of the alternators purchased at Autozone, you get what you pay for. Very well might be the gauge is inaccurate.

As satch has stated test the output of the Alternator. Spend $5.00 and go to harbor freight and get a multi-meter or go to Auto Zone or CSK/O'reileys and have them test the system in the car.

my 86 did the same thing needless to say i have a xtra alt, the gauge is most likely bad its the solder joints in the gauge try a junkyard or by a alt tester at autoparts store there only like $8 that an check ur fuses make sure there not rigged! IF BLOWN DONT USE FOIL THATS HORRIBLE!!!!!

As stated above, AutoZones "rebuilt" parts are mostly garbage. Even their new Duralast stuff is questionable. I went through four autozone waterpumps in less than a year on my Wrangler. Sure you get a lifetime warranty, but that doesn't cover the time you waste installing-removing-installing-removing.......... I only use AutoZone parts if they are made by a trusted manufacturer.

ya i know thats rite finally sum1 who believes in autozone i went through water pumps too in my 86 t bird it was like 6 in a yr then autozone and never had another problem!!! So stay away from advance

DISCLAIMER: Do this at your own risk!!!!

You can test the alt yourself, I'll get to the downsides of this method in a second, but here is the method.

Start car, disconnect positive battery cable and lay it in a SAFE place, like a few dry rags.

Hook up your multimeter to the engine and positive cable you disconnected. You can also test between the alt output and the intake manifold, whatever is easier for you. This will give you what the alternator is putting out.

So for the disclaimer part...

The battery, besides acting as a power source for the starter and acting as a power source for the alternators rotor winding, the battery does a good job at dampening and absorbing voltage spikes. Never drive your car without a battery. The test is safe, but do it quickly and carefully as to not cause any issues with the fuel injection system.

I'd recommend NEVER doing the above test. Not only is the battery a big capacitor which smooths alternator output, but without battery voltage to the field coil, the alternator voltage will increase. Sometimes over 18V.

They're both worthless. Step it up to NAPA and your bad parts problems will go away.