VW Beetle Forum banner

Battery draining overnight on 02 Turbo S

18K views 19 replies 10 participants last post by  vincem1099 
#1 ·
My wife's Turbo S has recently had a problem with battery draining overnight. I had felt that the battery was getting weak, but it tested as just low charge on a tester at Auto Zone. The alternator keeps the car running all day long. I recently installed a new radio, but ruled it out by pulling the radio fuse overnight, only to find the battery dead again.

I was reading in the forums here and elsewhere about the speed sensor going bad and causing battery drain. I have noticed during a few of the times we have jumped the car off, that the wing will move up and down right as I'm starting the car. Since this is only activated by the speed sensor, or bypass switch, I figure the sensor might be a possible solution to the drain.

My next test is to try the same trick with the fuse. I will pull the fuse that is on the speed sensor circuit, to see if that eliminates the drain.

Any other thought on this issue?

Thanks
 
#2 ·
Has it thrown any codes? I had same issue on my 02 and finally replaced the battery when it left me stranded and didn't have any more issues.


Sent from AutoGuide.com App
 
#4 ·
Could also be the monsoon amp.
 
#7 ·
I mentioned pulling the radio amp overnight and still had a dead battery in the morning. Seems from other posts I've read that the amp uses the same fuse as the radio, right?

I felt that the twitchy rear wing sort of pointed to the speed sensor. I pulled fuse 7 for the speed sensor, left it for 4 hours or so and it started strong. Hope it does the same in the morning.

Nice to have the amp location pointed out. I noticed that the rear speakers are not nearly as loud as the fronts, so figure the amp must be blown on the rear channel. I have an amp to put in and would like to use the factory wiring.
 
#12 ·
Unplugging Monsoon amp fixed drain!

I understand the parasitic draw test. The method of pulling one fuse or unplugging accessories one at a time helped me solve this. We don't drive the car all the time, so it was necessary to fix it fast. Plus my meter is being used by a family member.

After going all day without the Monsoon amp plugged in and then sitting overnight, we still have power! YEAH!!:)

Just wondering, does the Monsoon deck control the amp differently than an aftermarket deck does? Wondering if the amp is turned off by the OEM deck but somehow left on (drawing power) by an aftermaket deck. Ours was cold when I unplugged it, so it wasn't all the way on, but must have been draining current somewhere.
 
#13 ·
There's a fuse block on top of the battery. The big red wire should be the alternator wire. If it's melted, that could be the issue. I just had mine replaced. :eek:
 
#16 ·
The only thing missing now is running the factory speakers on the new head unit. Using the pinout diagram I found for the Monsoon amp, I managed to use some solid core wire as jumpers to send the powered output from the new head unit directly to the speakers without adding any wires. I had to crimp the ends of the wires to act as blades so that they slid into the factory plugs.

The only trick is that you have to look at the pin positions from the side that the wires enter through, since this diagram is actually the amp pin positions, not the cable.

The only thing lacking so far in this project is to actually use all 3 of the component speakers in the front. Since I have an amp I had planned to use, I'll likely just look for a cross over to work this out, since the speakers are actually in very good shape.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top