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Discussion Starter · #1 ·
You may recall I had an earlier post regarding some issue's I have been having with my '00 1.8T. Here is a quick summary of the symptoms:

1) Car will not start if left for more than 10hrs or so. I then need to boost my car. If I park it for less than this, it starts right up. I just had a load test done on the battery (only 6 months old) and everything checked out OK. The alternator light comes on when I turn the key and then goes out when it starts up. I believe the alternator to be OK. All wiring to the alternator seems secure.
2) The car has always "seemed" to turn over just a little bit slower than I would think it should. It doesn't bog or anything, but even in the summer it has the same behavior. This could just be my mind - I don't know. The car is well cared for as well.
3) Both of my seat heaters stopped working last week. Had a quick look at the wiring under the seat and it looks OK. Checked all fuses and they are good. Heaters do not work at any level.
4) My stereo stopped working this morning. Absolutely no power at all - fuse is fine.

Here are my guesses:
1) A short somewhere. Maybe a possible poor ground which is affecting these devices and causing a power drain?
2) Maybe an issue with my CCM? Are these devices controlled by my CCM? I'm pretty sure I don't have any water drainage issues but who knows... Perhaps I should check the CCM connections and such. Where is it located?

I am truly at a loss here and getting seriously frustrated. Any help or suggestions would be much appreciated.
 

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This doesn't seem CCM related to me. Here's some random thoughts...

Perhaps your load reduction relay has failed? Did you check all the fuses with a multi-meter? Did you check the fuses under the dash? Also, check that all the relays are seated properly, and the bolts on the connections under the dash are all tight. Check the battery cables for corrosion on both ends. make sure the negative is connected well to the chasis.

Power drain could be lots of things. Check to make sure your trunk light goes out (if you have a sedan) by folding down the back seats so you can see it.

Does your alarm, windows, door locks, and interior lights all work properly?
 

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Discussion Starter · #3 ·
Thx Soundguybob. I checked all the fuses in the main fuse panel but not any others "under the dash". Where are these located? I also pushed on the end of most of the relays which I could reach through the little hole above the fuse panel. The battery seems to be well grounded to the chassis. Battery terminals are clean and tight. I didn't check all the fuses with a multimeter, I just pulled them and had a look. Yes the door locks, windows, alarm, and interior lights all work properly. Exactly which devices does the CCM affect? Would you perhaps know if there is a main ground somewhere which handles the heated seats and stereo? It's kind of strange that they both don't work at all now. I'm frustrated because I know when I go to start my car tomorrow morning, I will need to boost it. Where should I start to look?
 

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Discussion Starter · #5 ·
Well, I pulled apart the lower dash and yanked the carpet up as well this morning. There was no evidence of any water under the carpet - it looked dry as a bone. I opened the CCM box and all wiring appeared to be solid. Also popped open the CCM and the circuit board looked clean and dry as well. I carefully looked over all the wiring bundles and didn't notice any corroded wires. Re-tightened all the ground connections I could see as well. Checked every single fuse and noticed that the radio fuse was in the wrong slot - my mistake (radio works now). Does anyone know which fuse controls the seat heaters? My fuse card doesn't reference one at all... I also checked all the alternator wiring again and it looks good. I think this means I must have a power drain somewhere. HELP.
 

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Discussion Starter · #7 ·
Thanks for all the advice.... My car started this morning but was very slow to turn over. I also took some readings with my voltmeter:

1) Battery voltage prior to start = 12.1V
2) Battery voltage after start = 14.7V
3) Battery voltage after turning on all accessories @ 2000rpm = 14.5V

My manual states the battery voltage (fully charged) should be between 12.4V - 12.6V. I got my battery load tested the other day and they said it was fine. Mind you I was driving it all day so maybe it was charged right up. Do these numbers look OK? Once again, the alternator light doesn't come on after starting so I think it should be fine. Should I get one of these full charging system diagnostic checks done? No idea where to start....
 

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No, 12.1 volts indicates about a 25% charge. You will have a hard time starting your car at that level. Your alternator is working fine but either something is draining your battery or your battery is bad. What is your battery voltage about 5 minutes after you shut your car down after a 15 to 20 minute drive? If it's not around 12.6 volts then I'd suspect the battery. If it is around 12.6 volts, then every hour measure the battery voltage and record the reading to get an idea of how fast it is discharging.
 

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The starting issue does sond battery related to me. Your CCM is fine. The heasted seats could be the fuses, switches, or burnt out elements. You can test the elements for continuity with a multimeter. I don't have access to my wiring diagrams at the moment, so I'm not sure off hand which 2 pins you need to check. Be VERY CAREFUL that you don't go near the airbag connections with the meter, as the voltage could set them off. The switches are harder to test, since they actually have a voltage regulator circuit in them, and will not test correctly without a load on them. So, if your elements are bad, the switches will apper to not be sending the proper voltage.
 

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Discussion Starter · #10 ·
REALLY appreciate the help - thank you. I took my car for a 20 minute drive to bring the battery up to full charge. Here are the readings I took after I parked the car:

1) 0mins = 12.7V
2) 20mins = 12.5V
3) 60mins = 12.4V
4) 120mins = 12.4V

I am going to take some readings for the next couple of hours as well and then post. Does this preliminary data point to anything? TIA.
 

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Discussion Starter · #12 ·
Promise - last reading.....

6) 240mins = 12.2V

In a matter of four hours my battery has gone from 12.7V down to a low of 12.2V - a little over 0.1V/hr average. This seems like quite a significant power drain to me. Let me know what you guys think....
 

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The curves below show battery voltage in several states of discharge where C=the amp hour rating of the battery. So if your battery would be rated at 100 amp hours, the top curve would be a 1 amp discharge rate, the next would be for a 5 amp discharge, 10 amp for the next, 20 amp and finally 33.4 amps for the bottom curve. Since your initial voltage and first reading were 12.7 and 12.5 volts, your discharge rate is probably somewhere around the c/100 and c/20 curve. Assuming a 60 amp hour battery rating range, that would be about 0.6 to 3 amps of discharge. There are other threads where members have measured there discharge rates and IIRC the rates were in this range. If you are sure your battery is good, then the next step is to put an ammeter in series with the battery cable and begin pulling fuses until you find what is causing the drain as indicated in the thread.

 

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I agree w/ kenblasko about using the ammeter, but only if you're really confident that the battery is good. I've had 2 batteries that were brand new off the shelf that would not start my old car, but tested ok with a load test.

Have you tried disconnecting your battery, and checking if the voltage drops with it not connected to the car?

Another thought I just had... The CCM will get confused sometimes if the voltage goes low enough that the car needs to be jump started. The fix is simply disconnceting the battery negative for a minute. The CCM is supposed to go into a sort of "sleep mode" after the car has sat idle for awhile, I think faster when the alarm is activated vs. when it's not. The sleep mode draws less power from the battery, so if it's not going into that mode, then it could cause this.
 

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Discussion Starter · #15 ·
I am going to attempt to get a replacement battery to see if that fixes things. They hooked up their load test machine to my battery, it did some diagnostics for about 45secs and then it said "Battery OK". I'll get them to test (or hopefully replace) it one more time to see what they say. BTW - my battery voltage after 14hrs was 11.9V. Car just barely started.... The battery has a 60 amphour rating.
 

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Discussion Starter · #16 ·
OK - here's a quick update... Got home from work today and immediately pulled the cables off of my battery. Took an initial reading and the voltage was a little above 12.5V. Battery voltage remained steady at around 12.5V for the following three hours. Unfortunately, I guess this means that I likely have a power drain somewhere that I have to chase down. Based on these readings, should I rule out the battery as a suspect and start pulling fuses as detailed in the other posting? Is it worth replacing the battery anyway? I also checked the drain a few minutes ago by locking the doors, pulling the neg. cable while connecting my ammeter in series. On the ammeter I had the red cable plugged into the "10A" slot and the dial turned to the "10A" setting - is this the correct way to read the power drain? The reading I ended up getting was a solid 0.39 on the display. A few questions:

1) Does the amount of my power drain point to a particular circuit or something? Can I rule out any circuits?
2) Should I pull all the fuses (one at a time)? Not sure if I should check the smaller fuses as well.
3) What sort of drop should I expect to see which would indicate I have found a problem area?
4) Would it be worthwhile to still get a full charging system diagnostic check done or will my initial testing suffice?

Thanks again.....
 

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Did you follow kcompton's advice in the other thread when measuring the current? As kcompton says, the hood alarm switch should be disconnected and the doors closed, ignition off, all accessories off and wait 15 minutes after removing ignition key before measuring current. If you did and you have a OEM radio, then maybe it's your radio / amp. There is a TB on the premium V radio causing battery drain where it says the drain could be in excess of 320 mA (0.32 Amps). So, I'd start with the radio fuse and then pull one fuse at a time. The typical drain should be less than 65 mA (.065 Amps) and more in the 25 to 45 mA range, so I would expect a significant drop of over 0.3 Amps if your 0.39 Amp reading is correct. As far as a full charging system check, based on the battery voltage staying constant for 3 hours after it was disconnected and the fact that it tested okay before, my guess is your battery is probably okay.
 

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Discussion Starter · #18 ·
Thanks Kenblasko. So I guess the first step is to properly measure the current. I measured it with all doors closed/locked but I obviously had the hood open. I took the reading right after I locked the dooors. Where is the switch located? That other thread mentioned it was under the latch somewhere - I took a quick look and couldn't see anything. Yes, I do have an OEM radio - not sure if it is the "premium V". I think it is the base/plain jane version.
 

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Look on the lower passenger side of the hood latch mechanism. You'll see a small microswitch and very small electrical connector. You might have to cut the small cable tie on the wire to the connector and gently pry the connector off the switch since it's it in a tight spot with little room for large fingers or maybe pliers might allow you to get a grip on the connector. Also, I don't believe kcompton has a premium V radio yet his drain was the radio.

Since yours is discharging fairly rapidly, you could also test the radio first by pulling the radio fuse and then measuring your voltage every hour or so to check the discharge rate.
 
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