TheSamba.com :: View topic - battery light on. after body work. no charge to Battery?

Sun May 11, 2014 4:35 pm

crazyvwvanman wrote: We know the alternator is not charging. But we don't know that it is because the alternator is broken. The blue wire circuit feeds key-on power to the alternator to initiate charging. Make sure this activation power is getting to the alternator. If it is, then blame the alternator.

Mark
Ok how do I trouble shoot this, obviously I have nothing on this circuit, Is there a fuse? where is it?.
Bently is not showing anything
I have evrything open right now, It all looks visually fine, engine starts and runs fine.

Sun May 11, 2014 4:43 pm

Look at the back of the alternator where the small blue wire is supposed to attach. Is the small blue wire attached? If you feel the wire does it seem sound?

When you just turn on the key does the alt/bat warning led come on solid?

With a voltmeter put one probe on clean engine metal and the other probe on the main threaded stud on the back of the alternator, where the red wires attach. Is there 12 volts there?

Now, with the key still on, move the probe from the red wire stud to the small blue wire attachment point metal. What voltage do you see?

Mark

Sun May 11, 2014 4:52 pm

crazyvwvanman wrote: Look at the back of the alternator where the small blue wire is supposed to attach. Is the small blue wire attached? If you feel the wire does it seem sound?
All good very sound

crazyvwvanman wrote: When you just turn on the key does the alt/bat warning led come on solid?
Yes

crazyvwvanman wrote: With a voltmeter put one probe on clean engine metal and the other probe on the main threaded stud on the back of the alternator, where the red wires attach. Is there 12 volts there?
12.4(same as the battery)

crazyvwvanman wrote: Now, with the key still on, move the probe from the red wire stud to the small blue wire attachment point metal. What voltage do you see?
0.00V key on, engine not running...do you want engine running?

Sun May 11, 2014 5:11 pm

That is an indication of a problem. The blue wire is supposed to supply a small voltage FROM the dash to the alternator to energize the magnetic field so when the alternator starts turning it will also start charging.

It is possible that the blue wire is connected to the wrong place on the alternator. Can you post a photo?

It is possible that the blue wire has a break in it somewhere between the dash and the alternator.

It is possible that the blue wire splice connection inside the engine compartment wiring box is unplugged or making poor contact.

It is possible that something else connected to the blue wire is dragging the voltage down to zero.(GoWesty relay? try unplugging the blue wire from the GW relay and measure the alternator blue wire again)

Mark

goffoz wrote:
crazyvwvanman wrote: Now, with the key still on, move the probe from the red wire stud to the small blue wire attachment point metal. What voltage do you see?
0.00V key on, engine not running...do you want engine running?

Sun May 11, 2014 7:38 pm

crazyvwvanman wrote: That is an indication of a problem. The blue wire is supposed to supply a small voltage FROM the dash to the alternator to energize the magnetic field so when the alternator starts turning it will also start charging.

It is possible that the blue wire is connected to the wrong place on the alternator. Can you post a photo?
checked and double checked

crazyvwvanman wrote: It is possible that the blue wire has a break in it somewhere between the dash and the alternator.

It is possible that the blue wire splice connection inside the engine compartment wiring box is unplugged or making poor contact.
Both my fears..Ohmed the wires everything showed Zero V or .0xV

crazyvwvanman wrote: It is possible that something else connected to the blue wire is dragging the voltage down to zero.(GoWesty relay? try unplugging the blue wire from the GW relay and measure the alternator blue wire again)
Bullseye :D...thankyou Mark...I was ready to stop trying and start drinking,
you've saved another liver :D
Disconnected the GW. Aux system completely..pulled the + supply and the - battery, and the blue trigger from the solenoid.
Now I have engine start, batt light out, 14.5V at the Alt+ and at the start battery... :D :D :D
Now
..why did the GW Solenoid fail? why is this the result?
I tested the GW solenoid by triggering it isolated, and it works as it should.
OK so somehow the GW solenoid is now a Ground fault(per bently)
How/why?
This was a system in perfect working order..20 days ago?
Does a dead Alt, Kill a GW solenoid???
Stumped ?
Thank you Mark, I now have a good circuit. for my start/run battery
..just gotta figure out the Aux batt..conundrum :roll:

goffoz wrote:
crazyvwvanman wrote: Now, with the key still on, move the probe from the red wire stud to the small blue wire attachment point metal. What voltage do you see?
0.00V key on, engine not running...do you want engine running? [/quote]

Mon May 12, 2014 5:22 am

I'm glad you resolved things to the point where your alternator is charging again. One of my complaints about the GoWesty aux battery charging setup has long been the large extra load it puts on the blue wire circuit in some installations.

However, as much as I don't like the GoWesty clunker relay you have not quite proven that it is faulty and causing your problem because of the fault. Maybe, maybe not. It still could be that something else is wrong and the added load of the clunker relay is just making it much worse. If you connect the relay coil up to a 12v battery and measure the amperage it draws you can see if it is pulling more than it is supposed to. It should pull less than 1 amp, something like .7 - .8 amp. If the relay is ok you can still use it and simply connect it up to an "X" circuit control source instead of to the alternator blue wire circuit. For 86-91 vans this is a pretty simple change.

Mark

goffoz wrote:
crazyvwvanman wrote: It is possible that something else connected to the blue wire is dragging the voltage down to zero.(GoWesty relay? try unplugging the blue wire from the GW relay and measure the alternator blue wire again)
Bullseye :D...thankyou Mark...I was ready to stop trying and start drinking,
you've saved another liver :D
Disconnected the GW. Aux system completely..pulled the + supply and the - battery, and the blue trigger from the solenoid.
Now I have engine start, batt light out, 14.5V at the Alt+ and at the start battery... :D :D :D
Now
..why did the GW Solenoid fail? why is this the result?
I tested the GW solenoid by triggering it isolated, and it works as it should.
OK so somehow the GW solenoid is now a Ground fault(per bently)
How/why?
This was a system in perfect working order..20 days ago?
Does a dead Alt, Kill a GW solenoid???
Stumped ?
Thank you Mark, I now have a good circuit. for my start/run battery
..just gotta figure out the Aux batt..conundrum :roll: .......

Mon May 12, 2014 5:55 am

You could take advantage of this. :D

http://www.thesamba.com/vw/forum/viewtopic.php?t=594407&sid=762de073d656d4c39c30b3ecd5e268af

Mon May 12, 2014 8:07 am

I like the versatility of these instead.

http://www.ebay.com/itm/Sure-Power-1314-Battery-Se...4897.l4275

http://www.ebay.com/itm/Sure-Power-1315-Battery-Se...3f286d7d8c

Mark

Mon May 12, 2014 8:22 am

dobryan wrote: You could take advantage of this. :D

http://www.thesamba.com/vw/forum/viewtopic.php?t=594407&sid=762de073d656d4c39c30b3ecd5e268af
Mmm probably a good idea...will go nicely with the new upgraded Alternator
But I'll miss my little solenoid going "Boink" when I shut off the engine.

Mon May 12, 2014 8:28 am

crazyvwvanman wrote: I like the versatility of these instead.

http://www.ebay.com/itm/Sure-Power-1314-Battery-Se...4897.l4275

http://www.ebay.com/itm/Sure-Power-1315-Battery-Se...3f286d7d8c

Mark

Yep, good options also. :D

OP, Here is some good reading.

http://www.thesamba.com/vw/forum/viewtopic.php?t=360837&highlight=yandina

Tue May 13, 2014 8:01 pm

crazyvwvanman wrote: If you connect the relay coil up to a 12v battery and measure the amperage it draws you can see if it is pulling more than it is supposed to. It should pull less than 1 amp, something like .7 - .8 amp. If the relay is ok you can still use it and simply connect it up to an "X" circuit control source instead of to the alternator blue wire circuit. For 86-91 vans this is a pretty simple change.

Mark

Ok pulled the solenoid out of the van, and hooked it up to my power supply
If I put power on the trigger pole it operates perfectly, and closes the circuit on the 2 power connections.
If I ohm it across the trigger pole to the case I get 0.7
How should I do the Amp test?
..and by X circuit ..Do you mean the spades on the right side of the panel(power with engine on)..and Yes 86 van
And thanks for all your help ...I'll probably go with the blue seas unit, but I'd like to understand why this failed and how?
Thanks

Tue May 13, 2014 9:16 pm

Also just to recap
My Aux battery setup started as a GW kit.
What I learned from the forum is;
Plug the Aux battery + output, into fuse three(86 and later) this powers Acc. only( clock,radio,interior lights)..also lets you use solar to charge the Aux only
thru the cig plug. while parked
Run a heavy gauge wire direct from the +start battery pole, to the solenoid input pole (fuse it at the start batt pole)..this was a huge improvement over the GW fuse panel connection, improve Aux batt charging dramatically, and easier to do.
Hope this helps someone.
...BTW GW was very helpful verifying these changes when I called them for input.
..maybe they should offer a improved Aux batt kit for us tintoppers
Anyhow , I'll miss the little solenoids "Boink" under my seat..but I think a different combiner is in my future