Ack! I hate cars.... Freaking charging system pissing me off....

[jonnyGURU]

You'd think the fact that I used to work at a garage, I'd be over this. I'm probably freaking because it's one of MY cars and I'm over protective of my wife who has to drive it.

The other day, the car was in use (mind you with A/C and radio on) and it just STOPPED. Car would not turn over again. Battery completely dead. Tried to jump start it and it ran for all of two minutes and then died.

Towed car home and put battery charger on the battery as you can not test charging system with a dead battery. If the battery doesn't hold a charge then it's a no brainer that I have to replace the battery. Right?

OK... Battery holds a charge. I put a load tester on the battery and it's at 12.5V. I hit the load for ten seconds and the battery drops to 11.8. I release the load and the battery bounces back up to 12.1. Do it twice more and the battery bounces back to 12.1.

Sounds like a good battery, right? Problem's the alternator?

Get this.... test the alternator. Dead on 14.1V where it should be. Put a load on the alternator and it drops down to 12.1.

Sounds like the battery just died because of a power draw then, right?

Well, when I used to work in a garage, we used to have an inductive ammeter that you could clamp onto the battery ground and sense a slow drain. Of course, I'm a computer tech now so I don't have access to such tools to find out if there's something draining the battery, but a walk around the car finds NOTHING electrical on.

What's weird is if the battery was just plain dead and need of a charge, why didn't the jump start keep the car running? If the alternator works and all accessories are off, shouldn't the alternator keep the car running? that damn thing only ran two minutes and then cut off.

Any suggestions are welcome. The car is a P.O.S. Ford Escort of the 1994 variety.

Thanks!

 

[d33pt]

i still think it is your alternator. pull it out and let a shop test it. i dont think it should ever drop below 13v while the engine is running.

 

[jonnyGURU]

I never said it dropped below 13 when the car was running. It was at 14.1 when running.

When I said that the battery dropped below 12V, I was putting it under load with a load tester with the car OFF. Not on.

It only dropped to 12.1 when I threw the load switch on the load tester with the car on, and then it immediately bounced back up to 14.1.

I resist taking the alternator in to be bench tested for two reasons...

1. The alternator is a year old. Just replaced it. Sure, it doesn't mean it's not bad, but....

2. The guys that throw these things on a bench will use the same tools I do. Test voltage and then test with a load. An alternator is not considered bad unless it drops below 11 under a full load.

My wife is like, "take it to a garage" and I'm like, "so they can replace a battery and an alternator that doesn't need to be replaced and have the car die a week later? No thanks."

 

[Jzero]

<< Any suggestions are welcome. The car is a P.O.S. Ford Escort of the 1994 variety.

Thanks! >>



You're full of sh!t! Are you seriously making fun of me, or is this for real?
B/c I had a '94 Escort (white hatchback LX) that did the EXACT same thing. One cold morning it wouldn't start so I got a new battery.
Then the timing belt went so I replaced it and at the same time the Ford dlr said the alternator was bad.
Whatever. I jsut ignored it b/c it was charging, it just supposedly had a bad diode (I still don't buy that).
Then one time I couldn't get it started. They told me it was a bad alternator, but I pointed out a strange behavior where the radiator fan would blow even though the car was cold. So he told me the temp guage was bad, too.
So I replaced the alternator myself. It worked fine for a few weeks, and then....
One night I noticed the dashboard lights looked dim, but I thought it was just me.
The next morning the radio kept going in and out.
by the time I tried to drive home that night it wouldn't start.
I jumped it and left it connected to my brother's car for a few min until it could run on its own.
It started fine the next day. That night I tried to drive home to go car shopping and I noticed the lights slowly getting dimmer, and eventually the whole thing died again.
I towed it to the dealer and they told me that both the alternator and battery were bad.
I told him to find someone who would take it as-is for $500 and just forget it--I was tired of their crap car and their crap service.

 

[jonnyGURU]

Damn dude... You scared with that first line..... I was thinking "do I know this guy?"

Seriously, I know the car has electrical problems. The dash lights are GONE. Have been for a year. TheA/C clicks on and off at a whim, but I found that it's a bad terminal on the blower motor, but I found that since the blower motor is under the glove box that a good swift kick gets that started again.

Sigh....

Think I can get $1000 for it traded in on a Jetta Wagon?

 

[woodie1]

Not knowing much about this car.... Where is the voltage regulator? Part of the alternator or separate? Could one of the diodes in the alternator have trouble with high current load?

 

[SuperSix]

I would pull the battery and the alternator and take them to Autozone or Discount Auto and get them tested on their dedicated test machines...

 

[jonnyGURU]

<< Not knowing much about this car.... Where is the voltage regulator? Part of the alternator or separate? Could one of the diodes in the alternator have trouble with high current load? >>



It's similar to a Bosch unit where the VR is piggy backed onto the alternator. It was replaced with the last alternator.

Remember.... the alternator is getting 14.1V. That's dead on right for an alternator.

 

[Bleep]

if I were to make a guess, well i guess i am, A bad ground is what I would look for first. Does the gas gauge work?? Sometimes a bad ground will show up as a malfunction of the gas gauge in that it will on occasion show full when it is not. I am not familiar with your car but if it has push on terminals to the alternator that would be suspect also. It will really do weird things it will charge good with the car setting still but when going down the road and you get some vibration it will actually quit charging.
Bleep

 

[jonnyGURU]

<< I would pull the battery and the alternator and take them to Autozone or Discount Auto and get them tested on their dedicated test machines... >>



Again... I don't have much faith in their bench equipment being any better than the stuff I have left over from Monkey Wards. I'm more apt to just replace the battery pro rata at Wal Mart and if that didn't work, have a garage put an ammeter on the battery to see if there is drainage.

 

[Jzero]

<< Damn dude... You scared with that first line..... I was thinking "do I know this guy?" >>



ROFL. I seriously had to go look at your profile to make sure you werent' posting from anywhere near PA just in case you turned out to be the poor guy who bought my car!

 

[SuperSix]

<<

<< I would pull the battery and the alternator and take them to Autozone or Discount Auto and get them tested on their dedicated test machines... >>



Again... I don't have much faith in their bench equipment being any better than the stuff I have left over from Monkey Wards. I'm more apt to just replace the battery pro rata at Wal Mart and if that didn't work, have a garage put an ammeter on the battery to see if there is drainage. >>



Again, you obviously haven't seen the equipment they have as of late. LCD info screens, and the like. Why not pull the two most possible culprits and get them tested on good equipment? For free? I hope you don't get a welt from banging your head on a wall.

What other choices do you have? None. I would recommend Autozone, they seem to have the most up-to-date testing equipment.


And to even partially rule out the alternator because it's a year old is flawed too..

 

[jonnyGURU]

<< if I were to make a guess, well i guess i am, A bad ground is what I would look for first. Does the gas gauge work?? Sometimes a bad ground will show up as a malfunction of the gas gauge in that it will on occasion show full when it is not. I am not familiar with your car but if it has push on terminals to the alternator that would be suspect also. It will really do weird things it will charge good with the car setting still but when going down the road and you get some vibration it will actually quit charging.
Bleep >>



I'm inclined to agree, alothough the gas guage works fine and the terminals are screw on and not push on. I think it's a bad ground. Wonder how much an inductive ammeter would cost. Hmmm..... eBay?

Anywho... I'm more inclined to think it's a battery with a short even though it's holding a 2A trickle charge. I'm going to run the car for a day and check it with the load tester the next morning. See if I still get such good readings.

 

[Ornery]

I went through this on an ancient Chevy. Replaced the battery, then regulator, then alternator and it still wouldn't stay charged! Work was done by me, Sears and an independent mechanic. Turns out the wire coming from the alternator to the positive terminal on the battery, wasn't getting a good connection to the terminal. When we tested it for voltage with the engine running, we all put the probe on an area of the connector that had a good connection, so it tested good. If we had put the probe on the battery terminal itself, we would have seen that it wasn't getting any juice from the alternator. Basically, my whole problem was corroded washers that the connector was sandwiched between!

 

[jonnyGURU]

<< What other choices do you have? None. I would recommend Autozone, they seem to have the most up-to-date testing equipment. >>



I'm familiar with the up to date testing equipment. But the Bear ARPS that they use does nothing more than my analog load tester except for the timer that ensures that the load is held for no less than 10 seconds. Certainly that's better than the piece of crap that they use at Discount Auto Parts, but on a fully charged battery they're not going to get a different reading than me; digital versus analog.

It's like when you have a customer that says the CPU crashes when it gets to operating temperature but when you get it in the shop, you can't get the temp over 45 C under constant loops of 3DMark2001 and you don't have the customer's board, heat sink or know the environment that the case introduces. Know what I mean?

I'm going to test it again tomorrow after it's been off the charger for 12 hours. See if the battery actually HOLDS a charge.

 

[jonnyGURU]

<< If we had put the probe on the battery terminal itself, we would have seen that it wasn't getting any juice from the alternator. Basically, my whole problem was corroded washers that the connector was sandwiched between! >>



Actually common. I'm load testing at the battery terminals. When I used to have access to an ammeter, I would test at both the battery negative AND the alternator positive. As in your case, it's possible to lose conductivity somewhere at either point or some point in between.

DAMN! The more I talk about it, the more I want to find an inductive ammeter on eBay. :|

 

[jonnyGURU]

AAARGH!!!!

THESE went for only $24.99!!!! :Q :Q :Q

Hmm....
OLD SCHOOL. Worth a bid?

 

[SuperSix]

<< It's like when you have a customer that says the CPU crashes when it gets to operating temperature but when you get it in the shop, you can't get the temp over 45 C under constant loops of 3DMark2001 and you don't have the customer's board, heat sink or know the environment that the case introduces. Know what I mean? >>



No, I don't see the relation.

The way I look at it, you can remove the two most possible faults in the system, and eliminate them. Quickly, taking out the possibility of your "test" equipment being faulty.

You have an automated, computerized, motorized alternator tester? That also has advanced battery diagnostic routines built in?

I will bet that it's either your alternator or battery.

 

[yakko]

<< when I used to work in a garage, we used to have an inductive ammeter that you could clamp onto the battery ground and sense a slow drain >>

hahahaha!!!! We just used to take the ground cable off of the battery and connect a test light in the loop. If it lights up there is a draw.

 

[Jerboy]

Charging system is not too hard to diagnose, but take it into a shop anyways. You'll need a few large, speciality machines. Don't waste your money on consumer grade hand-held test equipments.


1. Leave headlight on for five min to remove surfance charge. If it's an old style battery with removable tops, test with hydrometer. Every cell should be around 1.27 Otherwise use a 0.5% accuracy DVM. It should be 12.5-12.6V.

2. After checking the charge, test the battery using battery load tester. Load it to rated test amp, 1/2 the CCA if not mentioned. Apply the load for 15seconds. The votlage shouldn't dip below 9.6V

If you pass both of these tests, your battery is probably ok.



These are charging system tests:


3. Connect an inductive pickup to positive cable from alternator. Start the engine. The current reading should be quite high at first to replenish energy used in starting and stay rather constant thereafter. Once the engine is started, all the load should be running off of alternator's power.

4. Test the current at battery's positive cable. There should be almost no current or negative current(charging). Positive current means your battery is losing charge.


There are several reasons you'd fail this test. Lose mechanical connection, faulty alternator regulator, slippage at serpentine belt.




<< Get this.... test the alternator. Dead on 14.1V where it should be. Put a load on the alternator and it drops down to 12.1. >>



That is unacceptably low for a running engine. The electrical common rail should be ~13.8V under load with the engine running. Assuming that rotor is turned at sufficient RPM, the regulator is supposed to increase field current to maintain a constant output. You likely have a faulty alternator regulator, failed stator winding or faulty alternator diodes. All of these requires you to remove the alternator. You can choose to swap it with rebuilt alternator or rebuild it yourself.

 

[jonnyGURU]

<< The electrical common rail should be ~13.8V under load with the engine running. >>



Umm... WHOA!

As you may (or may not) know, VWs often come with Voltmeters in the dash. The last 3 VWs I've had has had the VDO voltmeter guage and all of them would read 14.1 with the car idle, no load and would drop to 12.1 under load. When using a Bear ARPS machine I would often put a good alternator down to 12V when the load test kicked in. I can't remember seeing one fighting the load tester and maintaining 13.8V.

I hope that when I say "under load" that you all don't think that I'm just hooking a regunlar old multimeter up to the battery and am turning on all of the accessories, because I'm not. I have an actual load tester. Click it on for 10 seconds, get's really freaking hot and then gives you a voltage reading. With the AC, radio and lights on, the voltage does not drop below 13.8, but this is not much of a load and not a very professional way to test a battery and alternator. Just wanted to clarify that.

I completely forgot the hydrometer test, though.

I'll try that before I do another load test on the battery.

 

[Jerboy]

<< Umm... WHOA!

As you may (or may not) know, VWs often come with Voltmeters in the dash. The last 3 VWs I've had has had the VDO voltmeter guage and all of them would read 14.1 with the car idle, no load and would drop to 12.1 under load. >>



The voltmeter in the dash is a joke. It's there more for cosmetic and nay or yay purpose than anything. Kind of like tachometer on AT cars with automatic rev limiters. Many car accessories are designed for 13.8V and many simulators that lets you use car accessories in buildings actually puts out 13.8V. Connect a 0.5% or better accuracy digital multimeter to cigarette lighter if you want reliable numbers. With the meter connected, go drive around and check on the meter once in a while or set it to record the lowest voltage. It shouldn't dip below 13.0V






<< When using a Bear ARPS machine I would often put a good alternator down to 12V when the load test kicked in. I can't remember seeing one fighting the load tester and maintaining 13.8V. >>



Ok, you weren't too clear. I thought you meant standard load when you said to put a load on it. Well I was talking about under regular operating condition. Not when you push it to theoretical limit.

How fast did you turn the alternator while on the tester? Alternator can't produce maximum output when RPM isn't high enough.

I'd also test for parasitic load using a DMM. It will measure it to hundredth of an amp or ten-thousandth of an amp depending on the setting.

 

[ultravox]

Really crazy but you'd be surprised how often this happens......

check the light in the trunk to make sure it goes out when the trunk is closed..pull the bulb to be really sure.

 

[Shockwave]

Output under load would depend on load. Logic at its best If your only usin radio, it should maintain higher volts output then if you use radio and lights and AC and shower and dome light and search light and...you get the point.

Anyways, I had a RX-7 once. Alternator went out (Tested and replaced) Still, battery would loose charge. WTF. Had alt. tested. Good. Ok, changed battery. Had wiring checked. EVERYTHING was good. Everything worked. Figured a short. Couple days later, battery goes dead. WTF?! Had alt. tested AGAIN. I was there watching them. Testing good...Wait! All of a sudden, it quits chargin. I had recieved a flaky alt from the factory. It was possessed man, it would just charge when it felt like it. So, dont assume a short test is conclusive, I would do a long term test (couple minutes), then repeat the test again a few days later.
My .02

 

[jonnyGURU]

<<

<< When using a Bear ARPS machine I would often put a good alternator down to 12V when the load test kicked in. I can't remember seeing one fighting the load tester and maintaining 13.8V. >>



Ok, you weren't too clear. I thought you meant standard load when you said to put a load on it. >>



I only just said, "load tester" in my first post and then got into a discussion with SuperSix as to how I don't feel their equipment is any better at testing than mine. That's cool, though.



<< Well I was talking about under regular operating condition. Not when you push it to theoretical limit.

How fast did you turn the alternator while on the tester? Alternator can't produce maximum output when RPM isn't high enough. >>



The car was at idle. Only 800 RPM.



<< I'd also test for parasitic load using a DMM. It will measure it to hundredth of an amp or ten-thousandth of an amp depending on the setting. >>



One last thing I completely failed to mention which will likely make everyone think the problem is a short in the battery.....

When I put the battery on the charger after it was supposedly completely dead, it only took 2 hours of a trickle charge for the battery to be charged to the point where it could be tested again. Correct me if I'm wrong, but if a battery was COMPLETLEY dead, wouldn't it take more than 2 hours @ 2A to charge?

I think this idea should cinch this:



<< 1. Leave headlight on for five min to remove surfance charge. If it's an old style battery with removable tops, test with hydrometer. Every cell should be around 1.27 Otherwise use a 0.5% accuracy DVM. It should be 12.5-12.6V >>



You mean lights on for 5 minutes with the car OFF, right? Good idea. Although the load tester should have knocked off the surface charge, you can never be too sure. Leaving the lights on for 5 should bring that battery down to a real world level.

Just found a cell phone charger plugged into the cigarette lighter. So help me if that's what is killing this freaking thing.......



<< The voltmeter in the dash is a joke. It's there more for cosmetic and nay or yay purpose than anything. Kind of like tachometer on AT cars with automatic rev limiters. Many car accessories are designed for 13.8V and many simulators that lets you use car accessories in buildings actually puts out 13.8V. Connect a 0.5% or better accuracy digital multimeter to cigarette lighter if you want reliable numbers. With the meter connected, go drive around and check on the meter once in a while or set it to record the lowest voltage. It shouldn't dip below 13.0V >>



Actually, on a VW/Audi, the Voltmeter is wired directly to the alternator. Sure, amperage and wattage are relative, but voltage is voltage and this reading should not be "a joke" even if it's a typical Radio Shack voltmeter wired up to your car battery. It's still telling you the VOLTAGE of the charging system. How can this not be accurate?