Battery works, but turn ignition and battery dies...won't start without boost

[Buffet Boy]

Hey all,

I'm new to the forum but have an old '01 AZG New Beetle.

I tore apart my dash to fix my blend door issue for the air conditioning (btw still not fixed, was missing the pin bushing).

Since putting everything back together I've driven the car for over 1000km (mostly highway) over the past two weeks. I noticed a couple times that the car had trouble turning the ignition (getting that clicking noise) but eventually was functioning fine.

NOW this morning, I tried to turn on the car and the battery just dies. Nothing works. I can get the car running if I boost it using a powerpack.

I think the battery is fine. If I disconnect the ground, then re-connect my power locks work again. There is no check battery light either. My alternator was replaced with a used unit about 45k (currently at 323k) and the car drives fine once started up.

I took off my steering wheel again to check the electrical connections....everything seems fine. ANYBODY HAVE EXPERIENCE WITH THIS ISSUE? OR IDEAS? Much appreciated....thanks

[MyOtherRidesAVette]

Doesn't sound like an alternator issue for sure (but used? I hope you mean a reman). Sounds like the battery, regardless of any indicator light, and I read a thread recently, where it turned out to be a weak starter, wouldn't crank the engine fast enough to start, but as I remember they could start it with a jump. Autozone will check your battery for free, and also do a free install of a new one if that's the problem. It was a Corner Auto Parts Store that checked his and also was able to diagnose the bad starter. No lights, no code thrown either.

MORAV

[savethebluths.org]

The clicking noise would lead me to believe its the battery, check your cables to make sure they arent corroded and are tight enough, when you lose ground or have a weak ground it will give you that rapid clicking. Also you need to have the battery tested. If you're getting a single click it could be the starter or starter solenoid.

[MyOtherRidesAVette]

Ditto, checking and cleaning the connections, normally it is the positive side that corrodes, not necessarily what you see, but within the connection, and I have experienced this many times, on many side mount batteries, in other vehicles. The lights, etc, work fine, but the cranking amps are weak.

M.

[JP]

x3 check the battery and cables as well, do you have an aftermarket radio by chance? maybe it's not grounded correctly and is sucking the juice from the battery.

[Buffet Boy]

Hey guys, thanks for all the feedback and info. I pulled the battery and got it tested... apparently the battery is good and completely charged! Meaning the alternator is working too since it is charging the battery

I've concluded there's an electrical problem where the battery is not able to supply power to the vehicle...does this make any sense (alternator -> battery -> vehicle)?

UPDATE: Using a code reader, I get code P0606 - PCM Processor fault (PCM = ECM?)

[MyOtherRidesAVette]

Originally Posted by Buffet Boy

Hey guys, thanks for all the feedback and info. I pulled the battery and got it tested... apparently the battery is good and completely charged! Meaning the alternator is working too since it is charging the battery

I've concluded there's an electrical problem where the battery is not able to supply power to the vehicle...does this make any sense (alternator -> battery -> vehicle)?

Please help me solve this mystery :$

Well, you have eliminated the battery (at least it being good), we already pretty much eliminated the alternator, I assume while you had the battery out you gave all the connections a good cleaning (wire brush, baking soda, the like) at the battery.

1) Have you had the starter checked? - see my post (#2) above (I can find the original post a week or two ago if you feel like you need to see it - I would have never thought it, but that's what the poster stated was the resolve.). You might also want to check the connections at the starter.

2) Is the battery of at least the size (cold cranking amps) as the specified, the fact that YOU CAN start it adding a "boost" would indicate the starter is not getting enough cold cranking amps to start the engine. Either a battery issue, or back to "1)", the starter. I believe there is equipment that can measure the cranking amps the battery is putting out when in the car and attempting to start it.

3) Does the positive cable appear to be the original? Sometimes too light a cable (wire size) v. distance can cause the problem you are having. [I had that problem (not at first and then only sporatic) with a factory harness on a '79 Corvette, which was solved by replacing the cable with a welding lead cable]

MORAV

[mlt]

This thread and pdf from there may be helpful VWVortex.com - P0606- '01 Jetta Throwing Codes like Mardi Gras

[Droid]

check the fuseblock above the battery.....heres why

any inductive load wants WATTAGE. period...not amps or volts...it's ohms law (amps*volts=wattage)....IF the fusible links in the little black box are crap (burnt up, fusing etc.) the starter cant pull enough CURRENT through the fuse, BUT with the addition of VOLTAGE (in the form of the power pack) you have increased the WATTAGE the starter can pull regardless of the amperage being pulled throught the fusible link....my guess is that the powerpack has a higher boost voltage than the battery voltage with no load.


its just a theory, but it makes sense...

[gamefoo21]

Did they load test the battery? With an actual capable load tester(most cheapies do 20-50amps you need a 100-150 amp unit)?

Sounds like the battery is weak. Get a cheap multimeter, hold it to the + and - of the battery and have someone crank it. How low does it go?

Originally Posted by Droid

check the fuseblock above the battery.....heres why

any inductive load wants WATTAGE. period...not amps or volts...it's ohms law (amps*volts=wattage)....IF the fusible links in the little black box are crap (burnt up, fusing etc.) the starter cant pull enough CURRENT through the fuse, BUT with the addition of VOLTAGE (in the form of the power pack) you have increased the WATTAGE the starter can pull regardless of the amperage being pulled throught the fusible link....my guess is that the powerpack has a higher boost voltage than the battery voltage with no load.


its just a theory, but it makes sense...

Over complication...

Without Voltage, Amperage is meaningless... So Wattage goes out the window, because like you said you need voltage and amperage.

Voltage = Force
Amperage = Weight(simplified)

500,000 volt stun gun hits you with a max of 1 amp. But if you get hit with a few hundred amps, at 110v, you are dead.

It's why welding cables are rated in amperage.

If he's hooking the booster to the battery terminals, then the battery is hooped, and he's hooking the booster up improperly... Positive goes to positive post, Negative goes to a good engine ground point.

If he's hooking the booster up properly, it's probable the ground cable is rotted and incapable of delivering the current needed. The factory cable bolts to the battery tray and the motor, the battery tray mounting point is very susceptible to corrosion and because of the need to cut costs/weight, the cables when new are on the edge, add years of corrosion and you end up with a no-start situation which can almost always seem intermittent, it'll work after sitting for awhile, or it starts in the mornings but not in the evenings/afternoons.

Wattage is good for making crappy speakers look good...