Where did you get the battery? What brand?
AGM batteries are overhyped, IMHO.
1.
Make sure all visible grounds are clean and tight.
2.
Make sure the alternator B+ eyelet is tight to the alternator.
3.
Check with the VW dealer if TSBs 27-05-01 & 27-05-03 had been done.
Clicky Here
4.
Check under the carped (driver side) wiring harness for compromised ground wire junction (corroded) due to water ingress or condensation. Re-crimp B- cables or solder them together.

When I bought my Egg, it had similar issues. It wouldn't hold the charge. I had to keep in on life support when not in use.
Since thorough cleaning and tightening of all B+ and B- cables, and adding extra ground straps between chassis and engine the draw is all but gone.

Also, do a parasitic draw test with a multimeter while pulling fuses out one by one to see which circuit is causing the parasitic draw.

Experience tells most small parasitic draw issues are caused by loose and/or corroded connections.

Cheers...

 

Where did you get the battery? What brand?
AGM batteries are overhyped, IMHO.
1.
Make sure all visible grounds are clean and tight.
2.
Make sure the alternator B+ eyelet is tight to the alternator.
3.
Check with the VW dealer if TSBs 27-05-01 & 27-05-03 had been done.
Clicky Here
4.
Check under the carped (driver side) wiring harness for compromised ground wire junction (corroded) due to water ingress or condensation. Re-crimp B- cables or solder them together.

When I bought my Egg, it had similar issues. It wouldn't hold the charge. I had to keep in on life support when not in use.
Since thorough cleaning and tightening of all B+ and B- cables, and adding extra ground straps between chassis and engine the draw is all but gone.

Also, do a parasitic draw test with a multimeter while pulling fuses out one by one to see which circuit is causing the parasitic draw.

Experience tells most small parasitic draw issues are caused by loose and/or corroded connections.

Cheers...

Where did you get the battery? What brand?
AGM batteries are overhyped, IMHO.
1.
Make sure all visible grounds are clean and tight.
2.
Make sure the alternator B+ eyelet is tight to the alternator.
3.
Check with the VW dealer if TSBs 27-05-01 & 27-05-03 had been done.
Clicky Here
4.
Check under the carped (driver side) wiring harness for compromised ground wire junction (corroded) due to water ingress or condensation. Re-crimp B- cables or solder them together.

When I bought my Egg, it had similar issues. It wouldn't hold the charge. I had to keep in on life support when not in use.
Since thorough cleaning and tightening of all B+ and B- cables, and adding extra ground straps between chassis and engine the draw is all but gone.

Also, do a parasitic draw test with a multimeter while pulling fuses out one by one to see which circuit is causing the parasitic draw.

Experience tells most small parasitic draw issues are caused by loose and/or corroded connections.

Cheers...

I managed to get it going. Will check all the areas you recommend. Thanks for the advice, it's greatly appreciated.

 

I need some perspective and advice with anyone who has delt with parasitic draw with the first gen.

If you want to see if there is a sizable draw, do not pull fuses, open/close doors etc. Every time you do that you wake up the car and you will always see a large parasitic draw that is really the TReg being ¨awake¨. You need to have a fully charged battery. I open the driver and passenger doors to have access to the fuses, the drivers seat already tilted back to have full access to the battery, and hood open. Then I trip/close all the door/hood latches. I use a steel ring about 3"in diameter to lock the hood latch. I use a screw driver to close the door latches. This makes the TReg think all the doors/hood are closed. Then it can go to sleep. You need to wait about half an hour or more for all the background systems to fully sleep. Also keep your keys far away from the TReg so they don´t trigger it to wake up. There are opinions on using a DC capable current clamp or adding up voltage drops across fuses to see what the sleeping drain on the system is. I used the voltage drop test since I didn´t have a DC clamp. What I saw was my drop was just high enough to slowly drain the battery. I invested in a $25 solar panel that I plug in the 12v power socket on the center console. It charges the battery and basically offsets most of the battery drain if I need to leave the car sitting for days. (outside in the daylight needed) I am not looking to find the drain anymore, I am managing it. i.e. I am bailing the water out of the rowboat as fast as its leaking and staying afloat. Battery is great. Always starts. Here is a great overview of looking for the drain.

 

Had me at bailing water to stay afloat.

 

I also linked to post so you could measure the voltage drop to see if it was consequential or not.

 

I need some perspective and advice with anyone who has delt with parasitic draw with the first gen. I have an 05 V8 4.2. Bought in December, Put a new battery in, had it parked when the fuel pumps when, figured I destroyed the battery by constantly starting it when the pumps when, ran for 30 seconds then died. Ordered the parts, waited for them to come, so I was down for about 2 weeks, battery was gone, dead, voltage down to 6v and destroyed a cell. Replaced that battery, to an AGM, was out of town for about 19 days, never thought to disconnect the battery. That battery is toast, will hit 100% on a charger, but the voltage is 6.7 according to the charger. That battery was installed at the end of February, and is completely tapped out, I've tried 24 hour trickle charge, multiple jump packs, the only thing that was able to give her life( but no turnover) was jump starting it from another vehicle.

Now I'm here, does anyone have any insight as to what could be causing the draw, I know this generation is plagued with electrical issues.
But before I get balls deep in this, a general direction on where to start would be great.

Also, would the rosstech system help diagnose some of these issues?

I appreciate any and all advice.

Do you have keyless entry on your Treg? KESSY's are notorious for parasitic draw if a module is down. Resistors and / or MOSFETS

 

If he has kessy he should check to see if the black buttons are shorted via VCDS live data. Normally antenna codes signal bad resistors/mosfets.

In general, a proper parasitic draw test may be in order.

And as mentioned previously, bad grounding will drain the battery.

Touareg ownership is rewarding

 

Just an update to this topic -- I came across these two documents that may assist in fault finding for others,


Direct download from NHTSA.GOV website:
https://static.nhtsa.gov/odi/tsbs/2015/MC-10121265-9999.pdf

Updated Technical Service Bulletin from March 2, 2022:
https://static.nhtsa.gov/odi/tsbs/2022/MC-10208920-0001.pdf