Went to start the car this morning. Nothing. The automatic seatbelts travel up at about 1/2 normal speed. Checked the battery with a volt meter and got a reading of 7.9 volts (battery is less than a year old). Checked to make sure that nothing was left on overnight, and nothing was. Tried to roll the car down the hill and bump start in 2nd gear (which has worked before). This time, nothing. Refuses to start. A neighbor stops and we try jump-starting. Still nothing. Won't even turn over. So, I call AAA, and the guy shows up about an hour later. He hooks up his little jump starter box, and presto! The car starts right away. Disconnect the jump box, turn the car off. Try the key again and it starts perfectly normally! I drive the car to the VW dealer and they perform a diagnostic check. Everything's normal. Since then I've started the car three or four times with no problem. I can't figure this one out. Maybe some weird internal problem in the battery?? Any ideas?
Mysterious Electrical Problem
djstewart
1 - 15 of 15 Posts
Went to start the car this morning. Nothing. The automatic seatbelts travel up at about 1/2 normal speed. Checked the battery with a volt meter and got a reading of 7.9 volts (battery is less than a year old). Checked to make sure that nothing was left on overnight, and nothing was. Tried to roll the car down the hill and bump start in 2nd gear (which has worked before). This time, nothing. Refuses to start. A neighbor stops and we try jump-starting. Still nothing. Won't even turn over. So, I call AAA, and the guy shows up about an hour later. He hooks up his little jump starter box, and presto! The car starts right away. Disconnect the jump box, turn the car off. Try the key again and it starts perfectly normally! I drive the car to the VW dealer and they perform a diagnostic check. Everything's normal. Since then I've started the car three or four times with no problem. I can't figure this one out. Maybe some weird internal problem in the battery?? Any ideas?
Re: Mysterious Electrical Problem (djstewart)
Start with the easy stuff. Clean both battery terminals and posts. The AAA guy may have made a better connection on one of them when he hooked up, and it's staying good for now. Take a hydrometer reading of the battery acid to test its condition and fill it up! Many of us are riding around with "maintenance free" batteries that are low on water. As one mechanic told me, "I've never seen a maintenance free battery". If your ground cable looks corroded and frayed, it should be replaced. You should also clean/wire brush where the ground cable connects to the tranny and the body.
Start with the easy stuff. Clean both battery terminals and posts. The AAA guy may have made a better connection on one of them when he hooked up, and it's staying good for now. Take a hydrometer reading of the battery acid to test its condition and fill it up! Many of us are riding around with "maintenance free" batteries that are low on water. As one mechanic told me, "I've never seen a maintenance free battery". If your ground cable looks corroded and frayed, it should be replaced. You should also clean/wire brush where the ground cable connects to the tranny and the body.
Re: Mysterious Electrical Problem (A2B4guy)
I point to loose cables, ground or alternator. As previously stated, clean this stuff up or they may be masking other more serious problems. Also, with a Passat and their quirky electrical systems, I wouldn't let this problem persist. One thing leads to another...
I point to loose cables, ground or alternator. As previously stated, clean this stuff up or they may be masking other more serious problems. Also, with a Passat and their quirky electrical systems, I wouldn't let this problem persist. One thing leads to another...
Re: Mysterious Electrical Problem (BC Dub)
BC is right, if the charging system isn't up to par, then other things will go bad, like your instrument cluster.
Also, don't rule out your battery. Get it tested to be for sure. Like A2B4 guy said, check the battery levels. If they are low, top them off with distilled or boiled water only.
Another thing, get your hands on a multimeter. Check voltage at the two battery terminals, with the car running. If it's low, check voltage on the alternator, with the car running. If the voltage is high at the alternator but low at the battery, then your cable connections are bad. If voltage is low at the alternator, then obviously the alternator is not putting out. Sometimes a new voltage regulator can save the alternator.
Just so you know, mycharging system is good, I have a brand new battery, new alternator, and clean cables. My battery sits at 12.7 volts with the car off. With the car running, the battery runs about 13.5-14.5 volts, depending on the power drain.
Hope that helps, and good luck.
Modified by Brett92 at 12:37 PM 5-24-2003
BC is right, if the charging system isn't up to par, then other things will go bad, like your instrument cluster.
Also, don't rule out your battery. Get it tested to be for sure. Like A2B4 guy said, check the battery levels. If they are low, top them off with distilled or boiled water only.
Another thing, get your hands on a multimeter. Check voltage at the two battery terminals, with the car running. If it's low, check voltage on the alternator, with the car running. If the voltage is high at the alternator but low at the battery, then your cable connections are bad. If voltage is low at the alternator, then obviously the alternator is not putting out. Sometimes a new voltage regulator can save the alternator.
Just so you know, mycharging system is good, I have a brand new battery, new alternator, and clean cables. My battery sits at 12.7 volts with the car off. With the car running, the battery runs about 13.5-14.5 volts, depending on the power drain.
Hope that helps, and good luck.
Modified by Brett92 at 12:37 PM 5-24-2003
Re: Mysterious Electrical Problem (Brett92)
Thanks for all the help, everyone. It has been 4 days, and the problem has not recurred. The dealership checked everything out on the day it happened and could find nothing wrong. I do have a voltmeter, so I will check alternator voltage at the source and at the battery.
Thanks for all the help, everyone. It has been 4 days, and the problem has not recurred. The dealership checked everything out on the day it happened and could find nothing wrong. I do have a voltmeter, so I will check alternator voltage at the source and at the battery.
Re: Mysterious Electrical Problem (djstewart)
That's what my voltage is.
Maybe you have a power drain somewhere? Maybe it's the ignition switch? I'm not sure. If you're getting good voltage to the battery, then your charging system is good.
Wait, Did you try checking the voltage at the battery with the car off? Check to see if your battery is losing voltage. I've left my car alone for a week and the battery still read 12.6 volts. If the battery reads high after you cut the car off, but reads low the next day, then you have either a bad battery, or a power drain.
Good luck.
| Quote, originally posted by djstewart » |
| I just checked the voltage. 14.4 at the alternator and 14.3 at the battery posts. |
That's what my voltage is.
Maybe you have a power drain somewhere? Maybe it's the ignition switch? I'm not sure. If you're getting good voltage to the battery, then your charging system is good.
Wait, Did you try checking the voltage at the battery with the car off? Check to see if your battery is losing voltage. I've left my car alone for a week and the battery still read 12.6 volts. If the battery reads high after you cut the car off, but reads low the next day, then you have either a bad battery, or a power drain.
Good luck.
Re: Mysterious Electrical Problem (Brett92)
Mystery solved! Yesterday, after work, I went to start the car. I knew the battery was dead even before I tried to start it because the central locking didn't work. Dead as a doornail. I flagged down a co-worker to get a jump. The revelation came as soon as we hooked up the jumper cables. Even though the car had been sitting for 9 hours, the radiator fan came on. That's the problem. The fan does not switch off on occasion and runs the battery down. I'm dropping it off at the dealer today. They replaced the fan control unit about 6 - 8 months ago, so I'm hoping that's the problem.
Mystery solved! Yesterday, after work, I went to start the car. I knew the battery was dead even before I tried to start it because the central locking didn't work. Dead as a doornail. I flagged down a co-worker to get a jump. The revelation came as soon as we hooked up the jumper cables. Even though the car had been sitting for 9 hours, the radiator fan came on. That's the problem. The fan does not switch off on occasion and runs the battery down. I'm dropping it off at the dealer today. They replaced the fan control unit about 6 - 8 months ago, so I'm hoping that's the problem.
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Re: Mysterious Electrical Problem (djstewart)
I wonder whether they should've replaced your fan thermoswitch (instead of FCU) if the fan continued to run.
Dealers swapping parts until a problem is solved =
![Image]()
![Image]()
edit: VR6 radiator fan thermoswitch is located in the top drivers side of radiator (not too far from battery). Just unplug the electrical plug if the fans run continuously. Don't do too much city or traffic jam driving with the harness disconnected from the t-switch.
Modified by Electron Man at 2:22 PM 5-28-2003
I wonder whether they should've replaced your fan thermoswitch (instead of FCU) if the fan continued to run.
Dealers swapping parts until a problem is solved =
edit: VR6 radiator fan thermoswitch is located in the top drivers side of radiator (not too far from battery). Just unplug the electrical plug if the fans run continuously. Don't do too much city or traffic jam driving with the harness disconnected from the t-switch.
Modified by Electron Man at 2:22 PM 5-28-2003
Re: Mysterious Electrical Problem (Electron Man)
The dealer just called. They can't get the problem to manifest. Hence, they're not doing anything.
![Image]()
Thanks for the tip on the location of the switch. I can at least disconnect when parking the car for a long period of time.
Modified by djstewart at 11:14 PM 5-28-2003
The dealer just called. They can't get the problem to manifest. Hence, they're not doing anything.
Thanks for the tip on the location of the switch. I can at least disconnect when parking the car for a long period of time.
Modified by djstewart at 11:14 PM 5-28-2003
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589 Posts
Re: Mysterious Electrical Problem (djstewart)
Check on the switch price, if it's not too bad, I'd go ahead and replace it. All you have to do is unscrew it from the radiator, and use a little teflon tape on the new one's threads and screw it into the radiator, and connect the electrical connection. If it is a lot, unplug it and watch the temp gauge in slow city traffic.
Check on the switch price, if it's not too bad, I'd go ahead and replace it. All you have to do is unscrew it from the radiator, and use a little teflon tape on the new one's threads and screw it into the radiator, and connect the electrical connection. If it is a lot, unplug it and watch the temp gauge in slow city traffic.
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544 Posts
another mysterious electrical problem
i'm having a mysterious electrical problem of my own. autozone tested the battery, alternator, and pep boys tested the started and they all tested good. so its either something to do with the ignition or i have a loose wire somewhere...and i think its a loose wire. sometimes i can push start it and then turn it off and it'd start back up, but lately if i do that it doesn't start back up. the other day i parked it up on a curb so i could get underneath it and take the starter out and test it. after putting it back in it started, i pull down off the curb and straight back into the parking spot, turn it off and then it doesn't start back up. so it sounds like there is a wire somewhere that is loose, but i haven't been able to find it. any ideas? i was going to have the dealer do a diagnostic test but they said it'd cost $100-200 just for that. does that sound right?? any help would be great.
i'm having a mysterious electrical problem of my own. autozone tested the battery, alternator, and pep boys tested the started and they all tested good. so its either something to do with the ignition or i have a loose wire somewhere...and i think its a loose wire. sometimes i can push start it and then turn it off and it'd start back up, but lately if i do that it doesn't start back up. the other day i parked it up on a curb so i could get underneath it and take the starter out and test it. after putting it back in it started, i pull down off the curb and straight back into the parking spot, turn it off and then it doesn't start back up. so it sounds like there is a wire somewhere that is loose, but i haven't been able to find it. any ideas? i was going to have the dealer do a diagnostic test but they said it'd cost $100-200 just for that. does that sound right?? any help would be great.
Re: another mysterious electrical problem (dqwolf1)
Its the afterrun fan switch if its running when
with key out. The one to the rad does not control the fan when the car is off. These things go. I asked the dealer once for a replacement part and he said " i dont show that on the computer" "You are Wrong" he said. Took it in and they said it was the Control Unit right off the bat. I said really? disconnected the single wire going to the afterrun switch located on the valve cover. It turned off. That was very funny and i guess i pissed the guy off cause he asked why i brought the car down if i knew what was wrong with it. Umm for you to fix it retard.
Its the afterrun fan switch if its running when
with key out. The one to the rad does not control the fan when the car is off. These things go. I asked the dealer once for a replacement part and he said " i dont show that on the computer" "You are Wrong" he said. Took it in and they said it was the Control Unit right off the bat. I said really? disconnected the single wire going to the afterrun switch located on the valve cover. It turned off. That was very funny and i guess i pissed the guy off cause he asked why i brought the car down if i knew what was wrong with it. Umm for you to fix it retard.
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589 Posts
Re: another mysterious electrical problem (netwerk)
LOL
![Image]()
![Image]()
for you
LOL
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