I own a 2003 Volkswagen golf. About 2 months ago I jumped the battery but crossed the jumper cables in the confusion of being late to something and having a dead battery. After seeing the problem I was able to start the car. After jumping the car the stereo is completely dead, no red flashing light or anything. Also the time is not appearing while the car is off and is reset every time I start the car. I checked all of the fuses and tried removing fuse 37 and 42 at the same time and replacing them with no luck. I have read that there is another fuse behind the stereo that you can get to by removing the stereo. Would this fix my problem? Did I fry some internal component by crossing the cables? Is there an easy fix that doesnt require a lot of money or taking the car to a mechanic? I have done quite a bit of research on this subject so far and have tried every troubleshooting option but checking the fuse behind the stereo. I sincerely appreciate any input you may have on this subject

SOURCE: 2000 Jetta Radio is dead after a dead battery jump start

Some German cars have anti-theft device inside to make it useless to steal...check at the dealership to see if jumping the battery will activate this(the car thinks its being stolen) .

SOURCE: 99 Passat blown fuse

I would certainly do that especially if it's an aftermarket radio which usually have it's own fuse. Let me know.

SOURCE: No radio and time & trip reset when car is off. After jump

We already know that's not a good idea. It causes havoc blowing as many fuses (which is better) and a real expensive disaster to the ones that were not fuse protected. Your alternator could be malfunctioning from this event and also consider solid state components be in a blown or fried state. Using a simple VOM will test for continuity of fuses and tell you if it's no good and replace the fuse. You've caused a disaster just by x-ing pollarity and by guestimating without the simpliest correct tools you will cause another which will burn a bigger hole in your wallet. The radio code is needed to unlock your radio. It is supplied in your radio owners manual and in a key tag attached to all your keys. For your instrument cluster I would think it's fried inside, rarely it could only be replacing the nicad battery that stores data for mileage info.

Steve Allison

• 5569 Answers
• Posted on Sep 28, 2009

SOURCE: 2002 golf . replaced battery 18 mounths ago now

You need to check if some accessory is drawing power when the car is not running.
About any inexpensive digital multimeter will have a 10 Amp unswitched range. You would need to detach the negative (ground) cable from the battery and put the meter in series with the leads plugged into it to access that range. - Do NOT turn on anything while so connected! It will fry the meter. Normally, there will be a very small amount of current flowing even with everything 'off.' This is normal as there are things still 'on' even though the car isn't running; the ECU will draw a tiny bit, your radio will too and any kind of clock that keeps time will also draw some current.
If you find anything over 1 ampere, you have a problem which must be found as this will drain any normal battery over a two-day period.
One item may have a failed part and cause this; your alternator. It has semiconductor parts in it (normally 6) called diodes and if one has been slightly damaged, it can draw current from the battery with the engine off and not light the warning light on the dashboard.
Good luck-

Testimonial: "thanks for the info. just had my son get the battery checked at another place and they found a bad cell.original place of purchase showed it was good"