[LisaMarie]

my 19 year old daughter just purchased her first car. A 99 VW Beetle. We purchased it from a used car dealership we knew little about (First mistake!). The car is still under warrantee and has been "fixed" once already but is still having issues. I'm hoping someone can help us pinpoint where the issue may lie so we can have all our ducks in a row before we go back to these clowns.
The basic issue is the battery is not charging.
**It started when the car died and would only start after being jumped. We measured voltage with car off and on and were only getting about 11V. We replaced the battery and the voltage was then 12.5V when the car was off, but still 12.5 when it was running. We rev'd it up to 2500 RPM and no change so at that point we assumed the alternator.
**The car then had the alternator replaced with these clowns and they put in another new battery. Upon returning home the battery was 12.5V off and on still. 12 hours later the battery reads 11.9 V off and on. Reving the engine to about 2500 RPM only gets the battery to a max of 12.4V.
** In my infinite wisdom (YouTube) I have figured out how to check the alternator output to the battery and the ground. I turned everything on in the car to "tax" the battery and it is dropping like a stone with the car running. I checked the voltage output to the battery from the alternator and got .9V. I checked the negative side to the alternator case/ground and got 2.14V. From the YouTube video I saw I believe both these readings should be around .2-.5 volts for minimum voltage drop across the cables.
Anyways...that's where we stand now. Killing battery #3 while testing. If anyone can direct me to try other things I will. We suspected a possible voltage regulator, but I'm clueless and was lucky to find the alternator. I would need some help in locating (also don't know if the 99 is an internal or external voltage regulatory).
Sorry for the long explanation....but any help appreciated as this dealership is also 2 hours away and driving a dying car back and forth is not an option. We'll be lucky if it makes the trip one way in this state.

 

[billymade]

While, I cannot give you specific help; I would say, just take the car to your nearest auto parts store; pretty much all autoparts stores will hook your vehicle up to a charging diagnostic computer for free and it will quickly tell you what the problem is. This is the easiest way to diagnose a charging problem; this way you don't have to remove the battery or alternator and can get a "real world" test with the complete charging system in the car. Unless it is a more in depth wiring issue or something else (other then a normal battery or alternator failure); a typical, free diagnostic check at a auto parts store, should give you the info you need to proceed with repairing your charging system in your new beetle. The check, will give you a "pass or fail, bad or good" answer; of either the battery or alternator. Hope this helps!

PS: if the car is still under warranty; why not contact whoever is honoring the warranty on the car? Why are you attempting to fix; something that is covered under warranty or is it? I would ask; before attempting to fix it yourself, it may or may not be fixed for free?

 

[LisaMarie]

Thanks for your reply! We actually did that before the alternator was replaced and one store said it was the alternator. The other said it was an alternator clutch???
Anyways. We have not done that since the replacement so a very good suggestion! Thanks!

 

[billymade]

Just remember; JUST because you put in a "new part"; doesn't necessarily mean the new part is not defective! It definitely happens; make sure you get a quality part, such a genuine rebuilt unit from Bosch, Hitachi, or Valeo... whichever yours is. The cheaper rebuilt alternators; can many times, not be very reliable long term and fail, causing you to swap them again! Hope this helps!

 

[esse10]

Battery problem

I believe most modern cars nowadays have the voltage regulator inside the Altnernator. When the car is at idle the voltage at the battery should be around 12.5-13.5 volts and that shows that the alternator is working correct. I would never trust a used car dealer to do any repairs in my car, they probably use salvage yard parts or something. JUNK! Make sure there isn't something that is still draining your battery aftery you turn the engine off. That has happened before with these beetles.
Good luck to ya

 

[jfoj]

I believe most modern cars nowadays have the voltage regulator inside the Altnernator. When the car is at idle the voltage at the battery should be around 12.5-13.5 volts and that shows that the alternator is working correct. I would never trust a used car dealer to do any repairs in my car, they probably use salvage yard parts or something. JUNK! Make sure there isn't something that is still draining your battery aftery you turn the engine off. That has happened before with these beetles.
Good luck to ya

Correction for accuracy, proper charging Voltage should typically be between 13.5-14.5 Volts. Baseline fully charged battery should have a terminal Voltage of 12.6 Volts at 75F as I recall.

There are some variations to the charging Voltage as some cars/trucks actually turn the Alternator off at times, like my GMC Truck, there is actually a current loop to monitor current usage/demand. So on these systems you have to be careful how you verify charging Voltage.

On these cars they should have a constant, uninterrupted charging Voltage supplied via the alternator.

 

[jfoj]

LisaMarie,

I just re-read your post in more detail.

Seems you have figured out how to test for Voltage drop. You CLEARLY have too much Voltage drop on the ground side.

One way you can cheat and verify that your Voltage drop is the problem, 2.14 Volts drop is BAD. Take your jumper cables and put a temporary ground in place. Use your negative jumper cable. Connect one side to the engine or alternator frame if you can get at it. Then connect the other side of the negative cable to the negative battery post. Check your Voltage at the battery with and without the negative jumper cable in place. You will likely see an increase of at least 1.5 or more Volts with the jumper cable in place.

12.5 Volt + 1.5 Volts = 14.0 Volts which would be a proper charging Voltage.

You either have a loose, missing or corroded ground on the engine. Likely if there was a clutch replaced or other major repair, the engine ground my be loose or disconnected?

There are also ground wires under the plastic battery tray as well, battery has to be removed along with the lower tray to access this ground location. You will likely find loose and/or corroded ground wires under the battery tray.

It may not be worth having the used car shop repair this issue as they may make problems worse, if you are reasonably handy you can sort the issue yourself and likely it will not cost you much if anything other than some time.

Good luck.

 

[LisaMarie]

I believe most modern cars nowadays have the voltage regulator inside the Altnernator. When the car is at idle the voltage at the battery should be around 12.5-13.5 volts and that shows that the alternator is working correct. I would never trust a used car dealer to do any repairs in my car, they probably use salvage yard parts or something. JUNK! Make sure there isn't something that is still draining your battery aftery you turn the engine off. That has happened before with these beetles.
Good luck to ya

Thanks Esse10. I was wondering if the alternator was internal and seems the most popular answer we've gotten is yes. As for the alternator I agree with you. These guys do not know what they are doing (they made that clear when they said they had to call VW and VW told them they could only use a genuine VW battery in the car. Realllllyyyyyy...even I'm not that dumb). Anyways. we are having our own mechanic who we know and trust look at it Friday but I'd like to feed him a little more information. Like you said to verify there isn't still a battery drain and it's funny you say that because we keep thinking there is. The car continues to lose battery charge even when not running. Can you tell me what this may be since you've said it's happened before with these beetles? Is it something specific? A combination of things? Any help appreciated!

 

[LisaMarie]

LisaMarie,

I just re-read your post in more detail.

Seems you have figured out how to test for Voltage drop. You CLEARLY have too much Voltage drop on the ground side.

One way you can cheat and verify that your Voltage drop is the problem, 2.14 Volts drop is BAD. Take your jumper cables and put a temporary ground in place. Use your negative jumper cable. Connect one side to the engine or alternator frame if you can get at it. Then connect the other side of the negative cable to the negative battery post. Check your Voltage at the battery with and without the negative jumper cable in place. You will likely see an increase of at least 1.5 or more Volts with the jumper cable in place.

12.5 Volt + 1.5 Volts = 14.0 Volts which would be a proper charging Voltage.

You either have a loose, missing or corroded ground on the engine. Likely if there was a clutch replaced or other major repair, the engine ground my be loose or disconnected?

There are also ground wires under the plastic battery tray as well, battery has to be removed along with the lower tray to access this ground location. You will likely find loose and/or corroded ground wires under the battery tray.

It may not be worth having the used car shop repair this issue as they may make problems worse, if you are reasonably handy you can sort the issue yourself and likely it will not cost you much if anything other than some time.

Good luck.

Jfoj - I will try what you said today by jumpeing the battery to the alternator. Just to make sure I'm understanding...in a sense you are using the jumper cables to make a direct connection between the alternator case and the battery negative thus removing the voltage drop across the current cabling and I should get the full 13.5-14V when I measure across the battery at that point correct? IF I get that voltage it should mean the alternator is working correctly and it's definitely a connection or corroded cable.

 

[jfoj]

LisaMarie,

No need for a special battery in these cars. Stupid VW Service Advisors that know nothing about cars, barely trained monkeys!

The Voltage regulator is built into the alternator on these cars. There are only 2 electrical connections to the alternator, the main power output on the large battery cable and one multipin connector.

Since you have a multimeter, if it has a 10 Amp DC measurement capability you can measure for draw while the sits. Anything above about 50-100mA is in question. Most cars have around 40-60mA draw when parked.

The other option is to just check the battery surface Voltage when the car is parked and check it again in the morning. Not 100% way to check it, you can get fooled by a weak/bad battery, but you will be able to figure out quickly if you are having a lot less available Voltage after sitting over night.

Note you should have 12.6 Volt at a minimum, anything less indicates a low battery that needs to be charged. With the alternator not charging, you battery will be low.

 

[jfoj]

Jfoj - I will try what you said today by jumpeing the battery to the alternator. Just to make sure I'm understanding...in a sense you are using the jumper cables to make a direct connection between the alternator case and the battery negative thus removing the voltage drop across the current cabling and I should get the full 13.5-14V when I measure across the battery at that point correct? IF I get that voltage it should mean the alternator is working correctly and it's definitely a connection or corroded cable.

Yes, you fully understand!!! This does not happen often that folks can understand the abstract nature of what we are trying to accomplish.

You are just adding a supplemental ground for test purposes and if you see a change, you know immediately that your original ground path is compromised.

You can even drive the car this way if needed, assuming you can get the jumper cable to stay connected and not interfere with the closing the hood and/or fall off while driving!

Good luck.

 

[LisaMarie]

LisaMarie,

No need for a special battery in these cars. Stupid VW Service Advisors that know nothing about cars, barely trained monkeys!

The Voltage regulator is built into the alternator on these cars. There are only 2 electrical connections to the alternator, the main power output on the large battery cable and one multipin connector.

Since you have a multimeter, if it has a 10 Amp DC measurement capability you can measure for draw while the sits. Anything above about 50-100mA is in question. Most cars have around 40-60mA draw when parked.

The other option is to just check the battery surface Voltage when the car is parked and check it again in the morning. Not 100% way to check it, you can get fooled by a weak/bad battery, but you will be able to figure out quickly if you are having a lot less available Voltage after sitting over night.

Note you should have 12.6 Volt at a minimum, anything less indicates a low battery that needs to be charged. With the alternator not charging, you battery will be low.

Trained monkeys - I agree!
I jumped the battery to the alternator and I get 11.9 volts while NOT jumped together and 13.2 when they are jumped together. That's only 1.3v, but it was just idling and I wasn't requested a charge on anything (by turning stuff on). Either way it's too much I believe from what you've said so that should point to some issues with cabling. On the positive side I had received about .9V drop. Is that too high as well?

As for the draw. We have been monitoring the battery daily at various times and actually this one is now low (because it's not getting the alternator charge) but doesn't seem to slip any lower than 11.9. Can you explain to me how to measure the draw? i.e. - where would I meaure the amperage while it sits?

Thanks for your patience with me! I know nothing about cars but have been spending a lot of time on the net and you tube and I do have an engineering degree (at least that's what the paper says) so I "should" be able to figure this out. LOL

 

[jfoj]

Your alternator is charging!!! So this is a good start.

13.2 Volts is slightly low, BUT you also have a battery that is very low on charge and it is likely drawing quite a bit from the alternator at this point. If you reved the engine up a bit, I would bet you would get into the 13.5+ Volt range.

For charging circuits, I like to see below 0.5 Volts drop and if possible less than 0.3 Volts drop. Here is the problem, you may find that even with all connections clean and tight you still have too much Voltage drop even with OE cabling. This would not the first time the OE cabling is undersized!!! Note for every 0.10 (1/10th) Volt drop you have in a circuit, this directly reduces your available Voltage between the source and the load. So if you have 2.14 Volt drop on the negative path and 0.9 Volt drop on the positive path, you are MISSING 3.04 Volts between the alternator and the battery/car. So assuming a full charging Voltage of 14.5 Volts - 3.04 Volt drop, you will never see any more than 11.46 Volts at the battery!! Also keep in mind, the more current passing though a bad connection/wire, the more Voltage drop that can occur. So my figures may be optimistic?

You may actually reduce your Voltage drop on the ground side even more as the jumper cables are likely inefficient as compared to a clean and quality ground connection.

I assume you are measuring the positive side from the output connection on the alternator to the battery positive terminal?

I cannot recall where the cable from the alternator leads to, I think it connects at the starter, then the starter cable connects to the battery and the battery cable has the smaller wire that feeds all the power in the car via the fuse box on top of the battery. I recall this is the path????

Other places to check to make sure things are tight.

Smaller cable connected to the positive battery terminal.
Wiring inside the fuse box on top of the battery.
Look for discolored and/or melting inside fuse box on top of the battery.

Also note, this may not be obvious, you cannot measure Voltage drop unless there is current flowing though a wire or connection. The more current flowing though a wire or connection, the more you will be able to measure any Voltage drop. Voltage drop is resistance, meaning bad/corroded connection or crimp or undersized wiring to begin with.

Sorry to see that you are more versed then the "mechanics" a the used car dealer!! You are actually more versed than over 60% of professional mechanics that earn their paycheck every day. Electricity is a VERY weak subject for both mechanics and electricians. It would scare you to death if you actually understood how little many of these "professionals" do not understand about their trade!

Good luck.

 

[jfoj]

As for current draw on the battery, I would wait a bit on this issue. Your car has some much Voltage drop in the current cabling while the engine is running, the alternator cannot get power to the battery or the accessories so you are constantly pulling power out of the battery.

Anyway, if you can take a good picture of the meter, I can tell if you have the high current measurement within the meter. If not, you can purchase a low value resistor and use the Voltmeter portion of the meter to measure current, but I will hold on explaining this for now in great depth.

What you essentially do is disconnect a battery cable and connect your meter in series. You can also use a low cost test light as well to verify, but not measure parasitic current draw.

You do need to be very careful as you can damage your meter if you do not know what you are doing and/or the meter does not have at least a 10 Amp shunt built into it, as well as a fuse to protect the 10 Amp shunt in the meter.

Also with most modern cars and truck, there are modules that do draw a fair amount of current that usually take 15-20 minutes before they shut down and go into a sleep or standby mode.

Also even opening the door without thinking can cause the fuel pump to prime, the interior lights to come on and the modules to wake up and this may exceed the capacity of the 10 Amp shunt/fuse within a typical decent quality meter.

So for now, wait on parasitic current draw as I doubt this is your issue, your entire car is a constant parasitic draw on your battery while it is running with the 3+ Volts of drop between the alternator and the battery/power center in the car.

 

[LisaMarie]

Your alternator is charging!!! So this is a good start.
13.2 Volts is slightly low, BUT you also have a battery that is very low on charge and it is likely drawing quite a bit from the alternator at this point. If you reved the engine up a bit, I would bet you would get into the 13.5+ Volt range.

YEAH! That’s what I figured! I figured also reving the engine would kick more out of it, but I’m the only one home so nobody to do that for me (i.e. sitting in the car) and I am not educated enough to know where to do that in the engine. I know you can, but don’t know where.

I assume you are measuring the positive side from the output connection on the alternator to the battery positive terminal?

That is correct. I watched a 15 minute you tube to figure that one out.

Sorry to see that you are more versed then the "mechanics" a the used car dealer!! You are actually more versed than over 60% of professional mechanics that earn their paycheck every day. Electricity is a VERY weak subject for both mechanics and electricians. It would scare you to death if you actually understood how little many of these "professionals" do not understand about their trade!

While I appreciate the compliment…I still don’t feel versed enough to change out these parts myself or fool with it too much! In a pinch – probably, but we do have a mechanic that we trust and who won’t perform unnecessary work which is rare! The more information I give him though the better I’ll feel.
Sad if that is true – electrical is weak for mechanics. It’s pretty much the guts of a car isn’t it? Cars not going anywhere unless you fully understand the circuitry! SMH

 

[jfoj]

Most likely problem with the ground path on the car:

Ground cable that I believe is connect to a transmission to engine bolt, likely missing or loose.

Next most likely problem is the ground connection directly under the plastic battery tray, loose and/or corroded.

Either one is not really difficult, basic hand tools and patience. But the connection under the battery tray requires battery removal and battery tray removal which is kind of a PITA.

As for YouTube videos, there are some good ones out there. Some not so much. But could you believe what would happen if every mechanic/electrician took 1 hour a month and actually watched some of these videos!! They might actually learn something.

Fortunately or unfortunately for me, I learned about about this stuff WAY before the Internet and I was lucky enough to have some VERY good instructors and we actually did a lot of hands on electrical work.

Matter of fact, I was able to solve some issues with my own personal cars. I learned that buying pre-made battery cables was a waste of time and money. I found a local place that would build up custom battery cables using 0000 welding cable (very flexible, multiple fine conductors and thick rubber insulation), quality solder on terminals and I could even have small pigtails added for both the positive and negative connections, all with color coordinated adhesive lined shrink tubing. The custom 0000 welding cables cost me less than the crappy 4 gauge auto parts store cables that was all that were available.

I was able to eliminate all by a VERY minor Voltage drop in both my starting and charging system!

 

[LisaMarie]

I would love to be that educated when it comes to vehicles! LOVE IT! I hate relying on people you don't know who usually take you for a ride and don't know what they're doing. I appreciate all of your help and it makes me feel better that the alternator is at least working and hopefully the cabling issue will be easy and inexpensive.
One last question (I may have missed this), but where would I measure the amperage when the car is at rest to see if there is a draw? That one you "may" lose me on....but shoot.....

 

[jfoj]

One last question (I may have missed this), but where would I measure the amperage when the car is at rest to see if there is a draw? That one you "may" lose me on....but shoot.....

Re-read post #14, I put some of the info about parasitic current draw in that post. BUT, I did not go into great detail as you can run into problems, possibly damage your meter, if you do not know exactly what you are doing.

Given you have a 1999 and do not have a Monsoon stereo system in the car, I would doubt you have a parasitic current draw.

As mentioned, an automotive test light can be a good indicator of a parasitic current draw, but even using one of these, you have to be careful how you interpret the results. Modules in the car have to be in standby or asleep.

Something like this - Amazon.com: Advanced Tool Design Model ATD-5513 Heavy Duty Circuit Tester: Automotive

You cannot get an absolute measurement using a test light for parasitic draw, however, you can get an indication if there is a problem. Test light in series with the battery cable (remove one battery cable connect one end of light to battery cable and the other end of the light to the battery post. No light is good, very dim light is likely good, bright light is bad!

As for relying on people for solid and proper advice, you think the automotive industry is bad! You have to watch the medial industry and be your own advocate. Dentist especially!!! I think people spend more time worrying about their car repairs than the medical needs. I think most people just believe their health care providers and NEVER question or look for a 2nd opinion. This is REALLY scary!

 

[LisaMarie]

Thanks so much for all your advice! you have helped alot!

 

[esse10]

battery

opcorn: Looks like jfoj has covered all the bases and anwered all the questions for ya. Hope you find that electrical Grambling in your beetle system.