[Doublel]

Hi Guys,
My wife and I just bought a 2003 Beetle 2.0L GLS with 128,00 miles on it.
It has been running great until today. We were driving today and I noticed the ABS and the airbag light come on. At a red light the brake light came on then when I started off the warning bell started dinging so I pulled into a parking lot and switched it off. Well then it would not turn over. It would try to but acted like a dead battery although lights and radio still worked. Had a friend come out and jumped it off and it started right up and drove home with no more problems. The only thing that I did before jumping it off was pull out the fuse at the battery which I don't know what they are for yet. A couple of the cables in the connection box on top of the battery are corroded and I intend on cleaning those tomorrow.

Any ideas as to what would cause this?

I've been a mechanic and an electronic tech my adult life and it leads me to think there is either a bad connection or a short somewhere
all of my experience is with American and Japanese cars, no European car experience so these are new to me.

 

[lovebug1959]

Sounds very much like a defective battery. The multiple positive and negative plates inside a battery can develop a hairline crack, and when this happens you can get an open circuit.

The symptoms are just like you described. One minute there is only the electrolyte fluid providing the circuit with enough juice to runs small items like lights but not enough to provide the amperage necessary to run the starter motor.

A jump start will often reconnect the plate that is cracked until such time that it expands to cause an open circuit again.

The multiple warnings lights that you experienced are likely the result of low voltage when the battery open circuit occurs. I've had this same experience myself a couple of times over the past 35 years of owning several cars.

This is very hard to diagnose because it's so intermittent.



I'm a retired license auto mechanic and know a thing or two about this kind of electrical weird stuff.

P.S. the fuse package on top of the battery is also crucial to be clean and tight on all the cables.

 

[Doublel]

You could very well be right. I didn't suspect that because the battery looks new but I will go have it checked tomorrow.

Thanks for that

 

[red99]

The fuse problem is common. If you search this forum for "melted fuse" you will find many such cases. Here is one:

http://newbeetle.org/forums/questions-issues-concerns-problems-new-beetle/28982-battery-fuse-box-melting-04-new-beetle.html

If you look at the first image you will see the fuse panel on the battery box. All the connections need to be clean and tight. On the left edge of the picture you will also see the connection from the fuse panel to the battery terminal. This also needs to be clean and tight where the cable connects. The lefthand fuse connects directly to the alternator so if the battery connection fails the voltage in the car's electrical system will go up to 16 volts since the battery out of the circuit. This can cause problems such as you have experienced.

Also, the main chassis ground under the battery tray can corrode. See:

http://newbeetle.org/forums/1-8-liter-turbo/58973-caution.html

 

[Doublel]

Any idea what the 40 metal fuse at the battery is for. Can't see it in schematics. Also what about the 3 plastic fuses at the battery.

Terminal for the alternator and the starter have been hot like they were/are loose. I am getting ready to clean those now.


Sent from AutoGuide.com Free App

 

[red99]

The large fuses from left to right are:

Alternator
Vehicle electrical system
Cooling fans (high speed)
Fuel pump
Secondary air injection motor

The smaller fuses left to right are:

Cooling fans (low speed)
ABS
ABS

The starter has no fuse. It is the other cable connected directly to the battery post lug.

 

[IndyTom]

Hi Guys,
My wife and I just bought a 2003 Beetle 2.0L GLS with 128,00 miles on it.
It has been running great until today. We were driving today and I noticed the ABS and the airbag light come on. At a red light the brake light came on then when I started off the warning bell started dinging so I pulled into a parking lot and switched it off. Well then it would not turn over. It would try to but acted like a dead battery although lights and radio still worked. Had a friend come out and jumped it off and it started right up and drove home with no more problems. The only thing that I did before jumping it off was pull out the fuse at the battery which I don't know what they are for yet. A couple of the cables in the connection box on top of the battery are corroded and I intend on cleaning those tomorrow.

Any ideas as to what would cause this?

I've been a mechanic and an electronic tech my adult life and it leads me to think there is either a bad connection or a short somewhere
all of my experience is with American and Japanese cars, no European car experience so these are new to me.

It's the Cable to the Alternator

 

[IndyTom]

The Large Black Wire goes to the Alternator. It builds up resistance over time and is a major cause of this Fuse box on top of the battery to melt down. If that wire looks bad or frayed in any way you should replace it immediately. Even if it doesn't it probably needs to be replaced since the ones from the factory weak and don't last as long as your car is old.

 

[IndyTom]