Aah! The battery isn't charging! Please help?

General_Failure Use your head, don't abuse it!

1,036 posts · joined Jun 2004 · 12 Aug 2008, 3:26 pm

#663614

Hello.

I just finished putting everything back together on my van after replacing a bad head, and after a few minor hiccups got it started.

One thing I noticed straight off is that the battery light wasn't coming on when the ignition is in the on position but the motor isn't running.

Secondly I checked the battery voltage. Hovering around the low 12v region. Not high enough.

Third, I spun the battery earth isolator out with the motor running. Please note I know alternators don't like this. But I also know that if the alternator is working the car will keep running. It Instantly stopped.

Given the symptoms what is the most likely culprit? It is an 1800 Type4 motor.
The charging system has always mystified me a little.

If at first you don't succeed. Build, build again.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 12 Aug 2008, 4:20 pm

#663621

most likely cos the charge light isnt working
i know on bug alternators the charge light completes the circuit with out it connected or the bulbs blown the alt simply wont charge
im guessing type4 alts are the same
find out why the idiot light isnt working and then check ur voltage again

greedy53 Bishop of Volkswagenism

3,062 posts · joined Mar 2006 · 12 Aug 2008, 6:02 pm

#663646

yep i can say from experance the light must work or nothing will a long sad tale so check the light and if thats ok well you know cry

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General_Failure Use your head, don't abuse it!

1,036 posts · joined Jun 2004 · 13 Aug 2008, 9:01 am

#663767

Not so ho on the crying part. That's why I posted here. The charging system has aways been a bit of a mystery to me. To make matters worse, it doesn't quite match up to the circuit diagram.

My van has a two pin regulator, and there is an extra wire running from the alternator to the starter. My guess is that is the wire that usually goes to the regulator... or something. All the alternator wires seem to have been spliced together at some point too. IIRC the colours are different on the wires. Not sure what that means, but it looks like a VW alternator to me.

On elast thing. I also pulled out the disabled remnants of the dual battery system I had setup. It was a simple design from that kombi camper site. If anyone has the URL I'd be grateful. I have a vague memory of it needing to plug into the alternator light wiring, but I'm pretty sure I used one of those double adapter blade adapters to achieve that.

If at first you don't succeed. Build, build again.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.

greedy53 Bishop of Volkswagenism

3,062 posts · joined Mar 2006 · 13 Aug 2008, 2:17 pm

#663802

SOUNDS LIKE AN OLD GENNY CONVERSION TO ALTERNATOR THESE HAVE ONLY 2 CONNECTORS AS A MATTER OF FACT CAN SOMWEONE POST A DIAGRAM OF THE WIRE CONNECTIONS AS I'M DOING THIS AT THE MOMENT AND I CAN'T REMEMBER HOW THEY GO

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Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 13 Aug 2008, 5:40 pm

#663821

Steve, its a pancake type4 engine, factory alternator
tristan the alt style regs were only 2 prong
and someones porbbaly just run a B+ wire from the starter to the alt trying to get extra juice to the starter motor

greedy53 Bishop of Volkswagenism

3,062 posts · joined Mar 2006 · 13 Aug 2008, 8:20 pm

#663863

thanks mate i'm droping an 1800 into my 72 and all the wires have been cut and its hard to see what goes where

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General_Failure Use your head, don't abuse it!

1,036 posts · joined Jun 2004 · 14 Aug 2008, 11:51 pm

#664043

I replied to this thismorning but it wouldn't send.

Short version, I found the problem. Green wire wasn't connected. All good now!

If at first you don't succeed. Build, build again.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.

mnsKmobi Wolfsburg Wizard

589 posts · joined Aug 2002 · 19 Aug 2008, 1:04 pm

#664775

General_Failure wrote:On elast thing. I also pulled out the disabled remnants of the dual battery system I had setup. It was a simple design from that kombi camper site. If anyone has the URL I'd be grateful. I have a vague memory of it needing to plug into the alternator light wiring, but I'm pretty sure I used one of those double adapter blade adapters to achieve that.

IIRC it uses the same logic as the heater booster fan i.e. the alternator light is used to drive a relay that connects the second battery only when the engine is running. Also you don't need to connect the batteries with a thick battery cable as a thinner wire will limit the current to the second battery. I think the logic is to have most of the current flowing to the main battery and accessories and a couple of amps charging the 2nd battery.