dead battery

[justdandy]

just got my '84 el Camino all synced and running fine. I was in a HEAVY rain, deep puddles, all's good. got to the store for a pack of smokes, turned it off. came out the battery was dead!!!!!. I don't have interior gages so I don't know if the alt was charging or not. It's suppose to be a 100 AMP, I had the A/C, wipers, headlights, and radio on also two cooling fans. I feel the 100 amp alternator should have kept up. I had to wait abt 1/2 hour 'till the battery regained enough life to start the car and drive home.
the accessories drive of V belts not serpentine.
this is a first time thing to happen, any thoughts?? thanks

dD

 

[Ernest]

Apparently you were running straight off the battery w/o it being recharged along the way, be sure to check all your connections thoroughly.

Since you dont have any working guages, its always a good idea to check the output at the alternator and at the battery terminals to make sure the voltage output, typical 14.4v is there while the car is idleing.

 

[78Delta88]

Figuring on OEM setup... If your running an 10SI or 12SI... With headlamps off, at idle turn on a turn signal, doesn't matter which.

If it clicks slow, give it some gas. As the idle speed goes up does the turn signal starts to click faster? If so, you have a bad internal regulator or not turning enough RPM to charge. Either way, check your system.

Check output, positive voltage drop and negative drop. Visual check connections especially at the battery and the sense wire. Particular to check is the 3/8 or 10 mm nut at the back of the alternator. When that gets loose you get internal arching and high resistance at that connection. If the plastic insulator fails you get a dead short and can have a fire.

Basically just do a good visual and physical check, then an electrical check with a volt ohm meter (VOM).

 

[69hurstolds]

100A alternator isn't factory. So whatever you got going on, it sounds like that might be a good place to start looking. But only AFTER you put the battery on a charger, give it a full charge, and then start the troubleshooting. Don't expect your alternator to charge up a dead battery. It's really not designed for that. Check the battery condition. Age of battery? Examine the cables, wires, clean and tight connections, and make sure there's no shorts, fraying, insulation damage, or missing stuff throughout the charging system. Also, if you have any peripheal grounds, check those too.

Belts tight? I mean, TIGHT? Slippage can be minimal but can affect performance. If you got a 1-wire setup, for a stock application, that wouldn't be my first choice. Nothing wrong with a stock internal regulator setup. If you start it, let it idle, it might not self-flash and not charge until you start driving.

There's usually a D-shaped hole in the back of the GM alternators that you can short with a small screwdriver inserted into that hole (BRIEFLY) while checkng Amp output. It'll bypass the regulator and go to 100% output. ONLY do this when set up with your ammeter on the red wire coming off the back ready to check amperage and only short it briefly. Prolonged shorting will damage the unit. It only takes a second or two to see whether you have full output. Many don't like doing this for fear of fugging something up, but it works. That's what the hole is there for.

 

[cloudhome]

If you've got a voltmeter, (even a $4 one from Harbor Freight), you can check if the alternator is working. With the car off, check the voltage. Start the car (assuming you've put a charger on it and got it to start again) and when it's running, see if the voltage is higher or lower. If it's higher, the alternator is working somewhat. If the same or lower, it's not doing anything. Second thing to check is the battery connections....make sure they're clean, and tight. Check also the thick red wire from the alternator to the battery terminal.....that's the charging wire.

 

[spongbob]

Couple points come to mind since your battery regained juice I'm certain
the batterys" good since a poor battery will not ! Water on a chrysler can cut it out for say a few minet 2 to 3 for example...sometimes ...a point I have learned is the battery voltage can be judged from the sound of the ac heater blower on high simply familiarize yourself to the rpm ( speed,) on high by listen to it several times when the battery and stuff are working ,once you learn this sound and revs you can simply snap the switch to high befor shutting down or when in question the fan speed will tell if the battery is as low as 10 volts in other words a couple volts low is the average cutoff for proper starter cranking ( in general)...knowing your low can help you decide what your doing next ,parking visual inspections or beating it to a certain place.... Let me say for younger drivers ect who aren't familier with v belts and altonators .. a loose belt can and we fail to charge a battery if your going fast it might work below 40 but above it can float up enough to cause a stalemate of charge verses drain ,they have to be tight! the belts in question also pull the water pumps"you likely will pull a pump with a loose belt ' but and altonator can turn 10,000 on the freeway..so you see . V belts can become glazed from slippage when that occures the belt will slip easier then ever..Recommendations rage from get a top notch belt also fingered belts ,( bottom notch ) pull better but need adjusted twice when useing them plus I think they can wear a little faster depending on who's driving habits are present...belts that contain extra cord can wear well but might be best suited to easy driving as they might float at some point in ther lifetime with aggressive use...I hope all this makes sence...to someone...lastly but not least a v belt can flip off at high speed say above 80 mph make shure you have and extra belt in your trunk..auto zones been know to test altonators but I have noticed they have on occasion been wrong..years ago when headlights were tungsten you knew voltage was low if the were visibly dim , especially if orange...nowadays the lights are led or halogen but tend to stay bright into the lower battery zones...be carefull when your voltage drops it could be a bigger problem then just a jump over .So get that car fixed "and drive responsibly or your car can cost you.... to much.....

 

[justdandy]

wow, yes, I went thru those checks, yes I was plowing water puddles, belts are old school plain V belts, no issues since. I've driven beaters all my life. yes thanks, the audible indications are best but some times tooooo late as in oil pressure. I digress, since the incident I've had no issues. it's been dry. belts are new. I guess I'll readjust a tad.
Thoughts, would a serpentine belt be subject to the same issues?

 

[78Delta88]

Not typically. The biggest killer to the serpentine is the tensioner and idler pulley.

The tensioner keeps belt in proper tension when working correctly.

V belts stretch over time and need periodic adjustments or they begin to squeal and the driven pulley is no longer at 100% capacity.