Won't start if headlights are on

miltoncf

Spammer
Joined
Jan 14, 2009
Location
arizona
TDI
ALH jetta wagon
Hello,

My 2003 ALH automatic used to have a cheap battery that lasted well beyond its 3-year warranty before having the kind of problems that a Walmart battery now has about half way into a 5-year warranty. Walmart just tested it at 620/750. Yet if I make a 1-mile trip and then try to start with the headlights on, the engine will turn without starting. So I usually pull up the handbrake to start, but even so, running the radio for about an hour also discharges the battery to the point where I'll need a jump start. Yet Walmart told me that their battery is still good (and that I don't need to have my receipt to invoke the warranty as they can trace my purchase via the battery's serial No). Your advice requested & appreciated on what to do next.

Milton
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Get volt meter.
Hook it up to the battery on DC volts when running. You want to see no less than 13.4 volts and no more than 14.4.
With the battery fully charged, turn your lights on for about 1-2 minutes to take the top charge off. You want no less than 12.4V Fully charged healthy battery is 12.6-12.8 and a new off the shelf battery must read no less than 12.8. now with the lights off and the meter hooked up to your battery and the fuel relay or 109 relay unplugged, crank it for 6-8 seconds and have someone watch the meter. you dont want anyting less than 10.0 amps on average.

If your charge is not within those readings, alternator is going bad, you can rebuild them or go OEM, do not go with a reman, even if its BOSH.

If your battery is less than the vales i gave you, than its going bad or is bad.

You can and should also test the amp draw on your starter when cold. Useing the amp function on the meter, test the draw on the starter at the starter, you dont want to see more than 80 amps typically. some starters take 100 amps to start but anyting like 120 amps is a sure sign of a failing starter.

3 years is typical life on cheep batteries.

You want it to last, make sure you keep a battery tender on it during the weekends or if its going to be parked for a week or more. after i started that, i have batteries that last 6 years on average.
 

Powder Hound

Top Post Dawg
Joined
Oct 25, 1999
Location
Under a Bridge, Crestview, FL, USA
TDI
'00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
A couple of other points to check might be the cables running to and from the starter as well as the alternator. Any oxidation on the connections will compromise the ability to run enough amps to turn the starter efficiently.

But more to the point, is there anything in the electrical system that is draining the battery while the car is off? There is a way to test for this, and you can find it here on this site if you search.

Another suggestion: A mile certainly isn't enough to recharge the battery to start a diesel. Considering the high compression and the draw to run glow plugs, you need a heck of a battery to turn even these small diesel engines over. If it is a marginal battery and not given enough time to run it sufficient to recharge, then you would be seeing just the behavior you are experiencing. I figure 7-8 miles minimum, and not at high speed, so 12-15 minutes of running to recharge from a single no-problems start.

Last, Walmart just isn't the best place for a battery for these cars. There's a reason people recommend the dealer unit. My recommendation is to check out Sam's Club for the Duracell labeled battery built by East Penn (who also makes the Deka brand). Look for an RC of at least 120 (the more the better) and in a group 49 size. It is big and heavy. It will fit, and you'll lose the outer battery box, but it is a good trade IMO since the battery will allow you to actually start your car more than once.

Price Club might also have a battery of similar amp hour capacity but since they don't have one close to me, I can't go check it out. The local FLAPS, IMO, are overpriced for what you get. (Like Wal-mart: too cheap.)

You will possibly be able to find the RC (reserve capacity) on the battery. Certainly you won't be able to find the Ah (amp hour) capacity of the battery (not in the USofA, anyway), but RC is a reasonable approximation. CA (cranking amps) and CCA (cold cranking amps) are next to useless. Your starter can't possibly use the amps promised in such numbers without melting into slag, and the real trick is how long the battery can provide those amps without the voltage sagging to unusable levels. Hence the insistence on the Ah capacity of the battery rather than the CA or CCA numbers.

Finally, to see if the battery just doesn't have the ponies for the job of starting, have someone run the starter on the second try while you put a voltmeter across the battery terminals. When you see the voltage dropping down into single digits after just a second or two, you know you have a battery capacity problem on your hands.

Good luck,

PH
 
Last edited:

drucifer

Veteran Member
Joined
Dec 21, 2013
Location
fredericksburg virginia
TDI
2004 jetta sw tdi pd
If you figure out if the battery is bad and you don't have any drains return the battery to Walmart long after the auto center is closed. Make your return at the servicenter desk make replacement group 49 h8. Explain your in the parking lot your car won't start, your multimeter says it's dead and you have a long way to go tonight. Walmart h8 batteries are listed as 140 RC. When I bought mine I had to dig a little but Amp Hours were at least 80. The added benefit is walmarts are everywhere and open at all hours. Batteries are also sold at stores without auto centers just make sure you get a fresh one.
 

miltoncf

Spammer
Joined
Jan 14, 2009
Location
arizona
TDI
ALH jetta wagon
I'll have to go when the autocenter is open, as I can't find my receipt, and then they'll want to test the battery and won't replace it if it's reading 620. However, it seems that this battery already needs to be refurbished, or at the very least needs equalisation, as it will start after short trips if it sits long enough for the battery chemicals to diffuse sufficiently. The most frequent problem tends to occur after a short trip having a short stop of a half-hour or less. One of those times a woman with a $40 jump-starter from Costco with a battery the size of a Betamax cassette was all that was needed. Even though my battery reads 620, that evidently isn't enough due to other things not being up to spec. Although the alternator must no longer be 100%, it couldn't have been much better over the first two years of this battery when all was well. So I'll be driving to Walmart after a short trip to have them experience said problem. It's ironic that what seemed to be a cheap battery from the dealer for only having a warranty of 3 years, outlasted the 5-years for Walmart's despite being one of their costliest (~$160) car batteries.
...
As for other drains on the battery, there's also dome lights that might stay on without automatically extinguishing, and an inverter to charge my cell phone. I know that's inefficient, but I'll have to hunt for a car charger on eBay, as the phone is too old have a USB port.
 
Last edited:

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
an inverter to charge my cell phone.
This could actually be a pretty large current drain (as opposed the current drain of an actual phone charger) since you're boosting the voltage all the way up to 115.. and then back down to 5. :)

How many watts is the inverter rated for?
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
if your battery is reading 620 out of 700+ then its probably fine but has issues, your starter is probably culprit but we have no idea as you must take a volt meter to it before going and wasting money on parts. Geeze! When a starter motor warms up it will pull more amps if its going bad. you NEED A MULTIMETER BRO.
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
A couple of other points to check might be the cables running to and from the starter as well as the alternator. Any oxidation on the connections will compromise the ability to run enough amps to turn the starter efficiently.

But more to the point, is there anything in the electrical system that is draining the battery while the car is off? There is a way to test for this, and you can find it here on this site if you search.

Another suggestion: A mile certainly isn't enough to recharge the battery to start a diesel. Considering the high compression and the draw to run glow plugs, you need a heck of a battery to turn even these small diesel engines over. If it is a marginal battery and not given enough time to run it sufficient to recharge, then you would be seeing just the behavior you are experiencing. I figure 7-8 miles minimum, and not at high speed, so 12-15 minutes of running to recharge from a single no-problems start.

Last, Walmart just isn't the best place for a battery for these cars. There's a reason people recommend the dealer unit. My recommendation is to check out Sam's Club for the Duracell labeled battery built by East Penn (who also makes the Deka brand). Look for an RC of at least 120 (the more the better) and in a group 49 size. It is big and heavy. It will fit, and you'll lose the outer battery box, but it is a good trade IMO since the battery will allow you to actually start your car more than once.

Price Club might also have a battery of similar amp hour capacity but since they don't have one close to me, I can't go check it out. The local FLAPS, IMO, are overpriced for what you get. (Like Wal-mart: too cheap.)

You will possibly be able to find the RC (reserve capacity) on the battery. Certainly you won't be able to find the Ah (amp hour) capacity of the battery (not in the USofA, anyway), but RC is a reasonable approximation. CA (cranking amps) and CCA (cold cranking amps) are next to useless. Your starter can't possibly use the amps promised in such numbers without melting into slag, and the real trick is how long the battery can provide those amps without the voltage sagging to unusable levels. Hence the insistence on the Ah capacity of the battery rather than the CA or CCA numbers.

Finally, to see if the battery just doesn't have the ponies for the job of starting, have someone run the starter on the second try while you put a voltmeter across the battery terminals. When you see the voltage dropping down into single digits after just a second or two, you know you have a battery capacity problem on your hands.

Good luck,

PH
Worth quoting. Thanks.
 

joetdi

Veteran Member
Joined
Mar 8, 2008
Location
Midwest
TDI
2-2002 Jettas W/Auto
You don't want to replace the alternator just because the voltages are not right. You need to know if the pulley is any good and that the wiring is ok first.

I've had problems with both.

Also is there a draw on this car?
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
If you're not willing to do the necessary diagnostics then seek professional help. Electrical issues will eat you alive unless you deal with them PROPERLY.
 

miltoncf

Spammer
Joined
Jan 14, 2009
Location
arizona
TDI
ALH jetta wagon
Last year I was running in the equivalent of limp mode for my car (at least when going up steep hills where I'd lose power before a downshift) after taking it to a garage that wasn't familiar w/VW TDIs (just Ford), but they did replace the whole pulley assembly for the timing belt tensioner. I then had to take it to TNT in Kingman AZ, which adjusted the injector timing for just over $100. The inverter is rated at 140 watts continuous, 300 peak, so it's even more inefficient than I thought, esp. as it runs hot even after the phone charger turns off. Interstate Battery did say that in most of Arizona, even a 5-year battery will have problems after 3 years, esp. if sealed. Still waiting for the right moment for a short trip to a Walmart Auto Center to see if my problem will happen to them.
 

miltoncf

Spammer
Joined
Jan 14, 2009
Location
arizona
TDI
ALH jetta wagon
Thanks, Andrew.
It's still less than 3 years so I should get a new battery, and asking for a less expensive one should make that easier. AS it happens, my battery failed in a Walmart parking lot w/an auto centre this morning, where two of its employees couldn't jump start me: one w/a portable battery, and the other with his Suburban. Afterwards somebody w/a pickup and what he called "high quality cables" got me started. He likewise thought that the battery chemistry had deteriorated, due to loss of water here in the desert. This time, I didn't make a short trip w/a short stop, but an hour's drive, letting the car sit overnight, so it's definitely so much worse since the last incident, that I shouldn't need to take it to Advance Auto for their diagnostics. Yet, since the H8 is also sealed, water loss will still be a problem, if only later than for the H7. I'll be posting what transpires at Walmart, probably later this week.
drucifer said:
The battery you have in your car is probably a 94r H7. Without tax or core $149. The battery I was saying to get is a group 49 H8. The specs on the bigger battery are 1000 cca. 140RC. and 80 amp hours. It only costs $122 before tax or core.
Andrew
 

tadawson

Veteran Member
Joined
Jun 14, 2013
Location
Lewisville, TX
TDI
2013 Passat TDI SEL, 2015 Passat TDI SEL
No lead acid family battery is truly sealed - all can vent, otherwise if something goes wrong (overcharge, etc) excess pressure can cause the case to burst. To that end, most supposedly "sealed" or "maintenance free" batteries still have caps that can be removed to test or add water if needed.

If this is happening a lot, you might have your changing system evaluated. Overcharging caused electrolysis loss of water . . .
 

miltoncf

Spammer
Joined
Jan 14, 2009
Location
arizona
TDI
ALH jetta wagon
Then Walmart only has itself to blame for not testing the water levels in case water needs to be added. It's unlikely that the charger has all of a sudden started to overcharge, but the same symptoms as loss of solvent can occur, if electrolytes in solution are increasing due to electrodes breaking down. So I took it back to Walmart late the next day, when it was a lot hotter, and their battery tester gave a reading of 122 F. And then they ran a load charge which alleged that it was delivering over 100% CCA, at ~760. This must mean that they're really measuring warm cranking amps, as another Walmart in the middle of winter measured 620 or just over 80% when it was in the 40s. I objected to the result on the grounds that when they hooked up a portable charger the day before at the morning low of ~60 F, the yellow LED came on indicating a battery between 30-70%. The auto center manager said that was a cheap tester, and the test he just ran was on a machine costing 1000s of $. I replied that the cheaper one obviously gave the correct result, given that neither the portable charger nor a gasoline SUV (owned by another Walmart employee) could get me jump started, and that I had to enlist someone w/a diesel pickup, who also thought the battery was the culprit. Even that didn't convince him, as he said it was policy to follow the readings from his machine. I continued to object and said that I couldn't risk stopping over in a place like Tonopah at 7000 feet, where the daily high is lower than his local low that was still cold enough to keep my car from turning over. Perhaps contingent liabilities registered with him, as that changed his mind so that they installed a new H7. I couldn't get the H8 (only 800 CCA btw) as it doesn't appear on their list of suitable batteries for my Jetta, which would make them liable if anything went wrong on account of that, esp as it doesn't fit in the frame which would have to be removed. If he and/or Walmart were smart, they'd use the tester like the one on the cheap portable unit, and ditch the one costing more, and taking more time. And they'd also keep a portable jump-starter specifically for diesels using high-quality copper cables.


No lead acid family battery is truly sealed - all can vent, otherwise if something goes wrong (overcharge, etc) excess pressure can cause the case to burst. To that end, most supposedly "sealed" or "maintenance free" batteries still have caps that can be removed to test or add water if needed.

If this is happening a lot, you might have your changing system evaluated. Overcharging caused electrolysis loss of water . . .
 
Last edited:
Top