[TouaregNut]

Hi guys, Happy New Year to you all.

So finally there is no charge going to the battery. In the morning when I started the car it was fine, I make a pit stop and I get battery warning light and things started locking down. I drove straight back home knowing very well my ass was in a sling.

Now my question, - Is there a way to test if the
GENNY stopped charging or if there is some wire lose. Sure the Gen had been acting up for a few months where it would suddenly go down to 13.5 and then come back up to 14. I just don't want to dive into the valley of death and see the Genny laughing at me....



Please advise

 

[SaVAGeSoot]

On the Merc?

 

[Touareg-V10-TDI]

You can take it to any Autozone, they hook up a charging computer, they can tell right on the spot if the alternator is charging or not. It is a free service on any Autozone and O'Reilly Auto Parts.

 

[TouaregNut]

You can take it to any Autozone, they hook up a charging computer, they can tell right on the spot if the alternator is charging or not. It is a free service on any Autozone and O'Reilly Auto Parts.

Yes thanks already tried, it no luck. What I am trying to figure out is if there is a point between the generator and the engine mounted terminals where I can tap into a wire that comes from the Gen.and get a direct reading. This way I will be able to make sure.

 

[Sceep]

I don't understand what you are trying to do.

Put a voltmeter on the underhood jumpstart terminals.
With the engine off, note the voltage. (likely around 12.5 volts)
Start the engine and note the voltage again. Shoud be 13.5-14 volts.
If it is still @ 12.5 volts, you are not charging.

 

[SaVAGeSoot]

 

[TouaregNut]

I don't understand what you are trying to do.

Put a voltmeter on the underhood jumpstart terminals.
With the engine off, note the voltage. (likely around 12.5 volts)
Start the engine and note the voltage again. Shoud be 13.5-14 volts.
If it is still @ 12.5 volts, you are not charging.

Here goes again - With the engine off I have almost same reading at the battery terminals and the terminals in the engine compartment. When i start the engine I don't see any charging. Now this could either be because of a faulty gen or a damaged wire. I don't want to pull the.gen and then find out the wire supplying the charge is broken. Hope this helps

 

[rgh0]

I interpet the statement "I dont see any charging" is that you see the voltage stay at 12.5 volts at the terminals in the engine bay with the engine running or not running

You need to access the wiring at the alternator to determine if anything is broken between the alternator and the rest cars electrical system. I dont how hard that is on the V10 but i presume it is not impossible. If all of that wiring checks out OK then the problem will be inside the alternator

 

[SaVAGeSoot]

Gas/Electric/Hybrid/Powertrain | V6, V8, W12, FSI

The 300SEL is not a V10 so I don't know what everyone is talking about.

 

[TouaregNut]

I interpet the statement "I dont see any charging" is that you see the voltage stay at 12.5 volts at the terminals in the engine bay with the engine running or not running

You need to access the wiring at the alternator to determine if anything is broken between the alternator and the rest cars electrical system. I dont how hard that is on the V10 but i presume it is not impossible. If all of that wiring checks out OK then the problem will be inside the alternator

Awesome 👌, thanks this is exactly what I wanted to hear. I will trace the wire coming from the Genny and tap into it to check for charging.

 

[TouaregNut]

Awesome 👌, thanks this is exactly what I wanted to hear. I will trace the wire coming from the Genny and tap into it to check for charging.

I think i might have found the culprit. There are two very fine wires blue and gray coming out of the regulator, the gray is pinched really bad. I will have to splice it and put a join, I don't think I will be able to pull a new one through the loom.

Does anyone know where these wires from the genny are connected under the drivers seat. I just want to run a continuity test.

Thanks in advance.