Flickering Dash Lights and Head Lights 2004 Jetta BEW PD

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2021 Atlas,2003 Jetta 261K Sold but not forgotten
'i heard the speakers crackling '

Should not crackle.
With the key off & out of the switch if you press the radio on/off it will turn on for a short period.
My Monsoon did anyway.

Try charging the battery with a battery charger for a few hours, then leave the battery disconnected for a day to see if it holds the charge.
Is there a parts store near you that can test it for you??
Some do not charge you if its bad & you purchase the battery.

Rich W.
 

r.korey

Active member
Joined
Jan 24, 2016
Location
Reno, NV
TDI
2003 VW JETTA TDI
The issue described matches what I ran into a month back, lights, dash board, abs giving crazy readings, the works.

There are battery negative terminal to the car body. To clean the contacts you have to take the battery and tray out, with a 12mm socket unscrew the capped nut that connects the negative battery cable to the cars shell. brush all the contacts down like mad and put it all back together. I can happily say my issue has been blasted to the past.

Cheers,
Korey
 

Mawcus

Veteran Member
Joined
Oct 5, 2012
Location
Bellingham, WA
TDI
2004 Jetta TDI BEW PD 5 Speed
grounds under battery have been checked. I saw no corrosion and everything was tight. I guess i can check them again take them off and actually clean them. The alternator charging cable was replaced at the beginning of the year and it fixed the constant flickering of lights i had.
 

Mawcus

Veteran Member
Joined
Oct 5, 2012
Location
Bellingham, WA
TDI
2004 Jetta TDI BEW PD 5 Speed
Voltage for properly functioning alternator?

Just got battery charged at Firestone. They said it was good. Hooked battery back up after car has been dead in driveway for a week or so. Below is a video of voltage with car running. Is this normal voltage for a properly functioning alternator. You can also hear the rhythmic fluctuation-stumble that goes away after a minute or two that ive described in earlier posts
https://m.youtube.com/watch?v=ly6WN6Cr-xc
 
Last edited:

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
The KISS principle. I for one have no idea how this could be TB related (That seems like the first thing people like to throw out there though)

I'm with Bob on this one.. Loose wire, connector, something stupid I'm sure.
Good answer. Let's see:

Do the lights flicker if the key is on and the engine is not running? if not, check charging voltage at the alternator and running and not running voltage at the battery. if it is good check for bad grounds and if its a MK4, check the box that sits on top of the battery for burnt wires and connections. If it is a MK5, also remove the air box and check the ground that is hidden under it.

A lot of folks have no idea of how to diagnose what a DTC is telling them. What they do is pull codes and replace what ever parts are named in the codes.

A CPS code does not mean the CPS is bad, as the OP found out. All it might mean is the CPS is not getting the correct clean voltage to function properly.

A failed T/B tensioner would not cause flickering lights.
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Below is a video of voltage with car running. Is this normal voltage for a properly functioning alternator
When I had a loose ground underneath the airbox, the alternator voltage would fluctuate. After tightening the ground, the charging voltage was pretty close to rock solid.
 

Rembrant

Veteran Member
Joined
Oct 31, 2014
Location
Canada's Ocean Playground
TDI
2013 Golf TDI DSG
grounds under battery have been checked. I saw no corrosion and everything was tight. I guess i can check them again take them off and actually clean them. The alternator charging cable was replaced at the beginning of the year and it fixed the constant flickering of lights i had.
A visual or tightness check for ground points may not be enough. You should remove each one and clean everything until the metal contact points are shiny clean. I just went through this with a low voltage issue.

Use sand paper, or wire brush, or wire wheel on a Drill or Dremel, etc, etc. Remove all corrosion.

For the Acorn nuts on the body grounds, lay your sand paper on the bench, and rub the flat surface of the nut on it until shiny clean.
 

Josh@jaztuning.com

Well-known member
Joined
May 5, 2007
Location
Eastern PA
TDI
Lots
I have nearly the same issue. Flickering lights at idle, rough idle, intermittent glow plug light on the dash when starting, etc.

When it is hard to start, do you notice the glow plug light is lit or not?

Mine doesn't turn on some times and then the car won't start. Have to turn the key a few times, and when the glow plug light comes on, it starts right up.

From there it may run ok for a bit, then idle rough, and then a bit rougher.

I replaced 109 relay thinking that might have been it and no go. Still on the search for a solution. Def. something electrical.
 

Mawcus

Veteran Member
Joined
Oct 5, 2012
Location
Bellingham, WA
TDI
2004 Jetta TDI BEW PD 5 Speed
Well i got the battery checked and charged at firestone. Checked out ok. Its been running fine ever since. Cleaned 2 of the 3 grounds under the battery tray. After sitting over night the battery is arou d 12.5-12.7v. Once started it jumps to 13.5ish with about .5v fluctuation. If i rev it up for a minute or so it jumps to 14.2v or there abouts. Considering getting a new voltage regulator but i dont know what kind of fluctuation warrants throwing a new regulator at it. Should have said this at the beginning of this post but i needed to put on my flame retardant suit first. I found that the passenger side rear door light may or may have not been on the whole time I've been dealing with this problem. I cant be for sure if thats it but i did notice yesterday that when i opened the drivers side front door that the light was on. Idiot! Maybe it was that simple but ive still got voltage bouncing around when the car is running. Maybe .5 volts of a jump. Wondering if this is enuff to throw on a new voltage regulator. My car is definitely not stable with voltage. Tested my 92 toyota truck and the gf's subaru...both with brand new batteries and the voltage stays steady when running...very little if any at all fluctuation. Maybe a couple .01v fluctuation. As of now everthing seems fine. Maybe voltage is a little low on a cold start up but none of the "tractor starting on a sub zero morning rumble". Just a tiny stumble for a few minutes and minimal flickering. To be continued
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Sounds like you're in good shape. You can only get a clue on the charging with a volt meter. Unless it is either getting nothing when you rev or staying at 14+ all the time (will burn up the battery). Abnormal fluctuation would usually be loose wiring. Did you clean the ground to the motor (top of transmission case)?
 

joep1234

Veteran Member
Joined
Jan 2, 2014
Location
NC
TDI
former '04 Beetle TDI, now 2x '15 Audi Q5 TDI's, 2007 Dodge Ram 4x4 6.7
Perhaps some other BEW owners could report their experience, but I don't ever recall seeing the tach read while cranking. Mine doesn't read until about 3 seconds after the engine is running.
Check your crankshaft position sensor. Your tach should read as soon as you start cranking. It should be over 250 rpm's for the ecm to start to fuel.
 

gojo71

Member
Joined
Jun 18, 2015
Location
Cincinnati, Ohio
TDI
2003 Golf
Quick question:
Bentley book states the following:
NOTE
The regulated voltage (engine running) should be roughly
between 13.8 and 14.5 volts, depending on temperature
and operating conditions. If the voltage is much higher
than 14.5 volts, the voltage regulator is most likely faulty.

I have had rough idle and flickering lights for a while. I just cleaned all of the ground connections and rough idle has gone away. I have monitored the battery voltage since and it sometimes goes as high as 14.5 volts while driving. Should I be concerned or not?
I have a 2003 VWGolf TDi ALH, not original owner but has 212000 miles and still going:)
 

gojo71

Member
Joined
Jun 18, 2015
Location
Cincinnati, Ohio
TDI
2003 Golf
Still flickering

So, update on condition......The lights are still flickering so I tried to start car with voltage regulator unplugged and the lights did not flicker. As soon as I plugged voltage regulator the lights started flickering. I looked at belt tensioner and it is bouncing....any thoughts on where to begin?
BTW the alternator, drive belt and tensioner was replaced 12/5/2015.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2021 Atlas,2003 Jetta 261K Sold but not forgotten
Did the alternator come with the clutch pulley?
When my pulley seized the tensioner bounced.
You have to take the belt off to check it.

Rich W.
 

gojo71

Member
Joined
Jun 18, 2015
Location
Cincinnati, Ohio
TDI
2003 Golf
alternator

The alternator came with the pulley attached. I am going to get the alternator and battery checked in the next few days. BTW light flickering is getting worse. Also will check clutch pulley tonight.
 

gojo71

Member
Joined
Jun 18, 2015
Location
Cincinnati, Ohio
TDI
2003 Golf
Flickering fixed

:) So alternator is covered under warranty. Replaced yesterday and so far no more flickering or bouncing of drive belt tensioner.
 

Mawcus

Veteran Member
Joined
Oct 5, 2012
Location
Bellingham, WA
TDI
2004 Jetta TDI BEW PD 5 Speed
well I'm stumped again. Thought i fixed the flickering problem. Replaced the voltage regulator. Everything seemed fine. Started it up cold and it ran smoothe right from the start. No stumbling, pulsing, or flickering of lights. I was stoked thinking i fixed the problem. Then maybe a week after replacing the voltage regulator i started noticing the flickering lights again and the pulsing/stumbling on cold starts. Stumped. I know it sounds wacky and unscientific but Its almost like the computer relearned the problem after installing the new regulator. Ran great for about a week then the problem came back. Gonna scour around for more info and see what i can find. Im tired of it!
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2021 Atlas,2003 Jetta 261K Sold but not forgotten
Then maybe a week after replacing the voltage regulator i started noticing the flickering lights again and the pulsing/stumbling on cold starts. Stumped. I know it sounds wacky and unscientific but Its almost like the computer relearned the problem after installing the new regulator. Ran great for about a week then the problem came back. Gonna scour around for more info and see what i can find. Im tired of it!
When it's flickering do a voltage drop test from the case of the alternator to the post of the battery. (not the cable connector)
I would not want to see more then 1/2 a volt and it should be solid not varying.
Same from the alternator + terminal to the battery + post.

I'm thinking there's a bad ground somewhere.

Also try an AC voltage test across the battery connectors.
This could point to the diodes in the alternator.

Rich W.
 

Mawcus

Veteran Member
Joined
Oct 5, 2012
Location
Bellingham, WA
TDI
2004 Jetta TDI BEW PD 5 Speed
Thanks I will check those things. One thing I did notice was that the part that the brushes make contact with (brass looking round things dont know what they are called) had some serious grooves worn in them from the brushes.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Unless the battery is way low, I don't see a bad alternator making dash lights flicker, maybe a very slight dim.
I'm guessing you've been over the grounds, I'm thinking some nasty wiring
 

magdoll

Member
Joined
Mar 24, 2011
Location
Chicagoland
TDI
2005 Golf
Did you ever get to the bottom of this?

Mine have been flicking bad for about a year, first thing I did was replace the alternator...

Same as you I thought it fixed the issue but about a week or so later I noticed it again...

Typically only happens/noticeable when the engine is cold but can happen anytime really.

Sometimes (rarely) I'll just use my power windows and that will be enough of voltage drop. To restart the radio and things like that...

I did notice we are both missing antennas but I'm really grasping at straws now...
 
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