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What is your question?
I have an unusually high drain rate on my battery when the car is not in use. If not used for several days the battery will go dead. Everything electrical works perfectly. The dealership acknowledges there is a drain but they can't isolate the problem. They say several systems have higher than normal electrical drain and it adds up so it kills the battery if not used and allow to recharge. This has been going on for years and when I took it in for service it showed no repair code. The dealership had just thought it was defective batteries. Now they say there is a problem they just don't know what it is. Any help out there?
2 Replies
The battery goes dead if left for several days. If the battery is really good it will pass a high rate discharge test and hydrometer test if left for several days it should read 12.6 volts if the battery is good.If the battery would typical go dead if left for a week, leave the battery disconnected for a week and see if it will start when reconnected if so the battery is good. Have they said how much the draw is. About .025 Amps is about right. With an Amp meter connected doors closed, keys out of ignition disconnect the fuses one at a time, disconnect the alternator and fuse links one at a time and see when the "draw" goes away, then with a wiring diagram the components on that circuit are checked to see which circuit or component is draining the battery.
I have a 2005 Jetta TDI with the same issue. (I bought the car used two years ago.) Since I park it in my garage I can keep it charged to keep the car usable while I troubleshoot it - a local electrical shop didn't want my business (what does that tell you) and a local German car specialist shop couldn't duplicate the problem / returned the car unrepaired. So, I purchased a dc ammeter that clamps around wires to measure current flow, since I seem to be on my own. My Jetta was flowing about 0.5 amp with everything off. I disconnected the accessory stereo memory unit in the trunk and it dropped to about 0.15 amp - this helped but did not totally eliminate the problem, which now takes longer to manifest. When the car doesn't start if I open and close the hood it will most often, but not always, then start. Other times if I loosen, wiggle and tighten the (clean) battery terminals the car will then start. One of my sons has a 2002 Golf with a similar issue and a neighbor with a 2000 Jetta has had a similar issue. Earlier today I was reading a Toureg forum thread with a similar issue (see VWvortex.com). So, it seems that several VW models have a similar issue - sounds like an electrical design issue with several models that have similar items drawing too much current with the car off. jclank77@charter.net
I am sorry to hear that you are experiencing the same frustrating problem. I ended up taking the car to a diifferent VW dealership and told them my story, that I had taken it in while still under warranty and wanted this problem fixed. They were also stymied by the problem and researched the problem with VW of America and after two weeks in the shop, found my car's problem. It was a faulty door module. Apparently the doors can draw power from both the module and the fuse panel. So, if you disconnect one it gets power from the other source. It made diagnosing the problem more difficult. I have not experienced a battery drain since they replaced the door module. Because I called VW America, opened a case and complained, they also did this as a complimentary repair. The only reason I believe they comped the repair costs was because I had brought the car in while still under warranty and the car was not fixed correctly. While my problem was the door module, I would certainly be suspicious of any of the modules. Good luck.
Thank you for your reply. I have already done the diagnostic steps you recommended. With a good battery, it will remain charged if I disconnect the battery connection from the negative pole. Regardless of telling what I had done to test the battery, the dealership replaced two batteries over the course of four years, claiming defective batteries was the problem. Recently, I diagnosed there was excess draw on the battery by disconnecting the negative terminal and placing an ohm meter between the negative cable terminal and the positive terminal. My wife also has a TDI Jetta and the difference was about a 1/3 higher. My results were confirmed by the dealership. The problem has been isolating the problem circuit(s). They have isolated all the fuses and all the modules and there is higher than normal resistance on several circuits, but not a root factor explaining why this is happening. So my car remains in the shop. They have engaged VW America's techs to see if they can discern the problem, but so far they haven't figured it out.