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2000 Passat 30V w/ 4-Mo @ 78k

(I'm posting this in the B5 forum also)

Long-time reader, first-time poster -

I know this is long, but for the love of God, PLEASE PLEASE HELP ME!

So I've read hundreds of old posts, and I just can't seem to put a finger on this issue. Seems there are MANY others with this problem, they post, people offer "you need a new battery" as a solution, and then the post dies off.

Let's put it to rest - I've replaced my battery three times to-date since July of 2008. Why? Every so often you go out to start the car, and the battery's dead for no rhyme or reason. Try to recharge it, and the battery's so fried it won't even accept a charge and it must go back to the auto parts store to get exchanged (again, three times now).

What it isn't: Interior lights staying on, glovebox light staying on, radio (HU) staying on

Until now, I didn't know what to think and figured just selling the thing was the best way out. Ultimately, I like this car and don't really feel like having a car payment again if I don't have to, so ideally I'd like to keep it around.

In the last 24 hours, I've spent a LOT more time on here reading old posts because it happened again- the battery went bad out of nowhere. "Bad" means it won't even work off the vehicle, btw.

I read the Mobile Electronics forum quite a bit, and identified a potential reason for concern- a recent HU upgrade to a Clarion DXZ385USB with a Metra harness, Part # 70-1784. Now if something was done wrong, I'm the one to blame, but I've done plenty of car stereos before, and figured this one was no different. I soldered and shrinkwrapped my connections, and terminated all the wires into the factory harness, powered it up, and everything worked fine. I didn't run any additional wires under the dash anywhere because, well, it worked, so what the hell was the point? Looking back, I put this radio in around July, and that's when the problems started.

What bothers me about this, like I said, is it just comes out of nowhere. I could go outside right now and meter the week-old battery (car hasn't been used in 24 hours) and it would be right around >12 volts. No problem. Fast forward a few weeks, and that's another story. The car will ALWAYS start strong, then all of the sudden out of nowhere, dead, nothing. I know the ECU needs X amount of voltage for the vehicle to start, but I'm saying there's NOTHING, nil, the battery is as dead as a doornail.

Having quoted Dickens, my day now feels complete.

Without a clue as to what could have been the cause, I spent some time the other night searching, and found a few posts about aftermarket HUs and Monsoon amps. One post in particular was similar enough to mine, so I went out to the Passat and tested the theory. Theory was, he had a phantom battery drain somewhere, and an aftermarket radio with a Monsoon amp that even after being parked overnight was still hot in the morning. Upon checking, my Passat which had been parked for eight hours in a dark, cold garage had a Monsoon amp in its interior compartment that was warm to the touch. The radio's off, no output on the front right speaker, so what's keeping the amp on?!

Question is, could this be my CCM? I read somewhere that the amp is controlled by the CCM (?). I removed my carpet to check the floorboards, and all in clear- no water, no damage anywhere that I can see.

As a sidenote, my keyfobs work fine (and when locked, the red LED on the driver's door DOES flash), but SOMETIMES if I try to manually lock the driver's door, the alarm will not enable. HOWEVER, sometimes when I open the driver's door, the interior lights will not illuminate, so, I think all this is is a bad switch in the DD latch assembly (which is tied to the manual door lock) and not relavent to the CCM. In short, I'm turning the key and the car doesn't realize it, then the interior lights come on and the alarm goes crazy.

I know that's a lot to bite off, but I literally tried to pour as much detail in here for the sake of time, and to prove I've done my archival research. If ANYONE can help me out on this, I SURE would appreciate it!
 

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this is not a CCM problem. I'm going to guess the problem is associated exactly where you think it is. there is (as you stated), another post just like yours. my guess is there is a connection that is made improperly to the metra harness. I'm going to ask you to take the time to pull the head unit, and list here where each wire is connected. if you still have the original wrapper for the metra harness adapter, you can list what each connection on the wrapper says it is supposed to go to as well.

the monsoon amp requires audio to be sensed on the input for it to turn on. any signal or voltage there will do it, do you see what I'm starting to get at? in addition, I suppose it is possible for the monsoon amp to go bad and stay on all the time, but probably not likely.
 

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Discussion Starter #3
Yeah- I've been looking for a reason to go outside and start ripping something apart, why not the car?

I'll go out and check it out, document everything, and post back here. Thanks!
 

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nore info is beter than no info - your original post was good, now go back out there and write everything down or take pix to boot. :thumbup:
 

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So I finally managed to get out to take a look at everything -

First off, I put a meter on the battery, which was EXACTLY 12VDC. Mind you, the car hasn't been driven for over 24 hours at this point. I popped the boot, opened the panel, disconnected the harness from the hot amp, and from across the car I saw the meter jump to 12.04VDC. Clearly I've identified the issue. Interestingly, once I restored power by reconnecting it, the amp did not power back on. I got in, turned the key, radio came on, engine started, and at idle I'm making approx 14.03VDC from the alternator, so I'm good there. Shut the engine off, voltage dropped to 12.65VDC. Got out, pulled the harness from the amp, and we're up to 12.69VDC, so this is a consistant issue, and not intermittant.

I'm staring at the radio hanging from the dash right now...

As far as colors go, everything's one-to-one, the only wires that aren't connected between the Metra harness and the Clarion harness are the Metra's PINK and BLUE/WHITE.

The PINK on the Metra appears to go to the factory harnesses BROWN/RED.

The BLUE/WHITE on the Metra appears to go to the factory harnesses GREEN/RED.


I know the reason can be found here, but now I'm getting badgered to go run out to the store. What's wrong with this picture?

Thanks!
 

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he just thinks he's amazing. really. no kidding.
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I think that when I installed mine, I didn't cut the red loop. But I'm not sure. If I have enough time I'll check my setup for you when I get back to my HU release keys.
 

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Discussion Starter #8
Thanks-

What do you mean when you say "red loop"?

As a sidenote, was I supposed to modify anything at the amp's end of the wire harness?

I appreciate everyone's help on this- 'til we have something, I'll just keep pulling the amp harness every night. Yay for that- good thing it's not a PITA to get to!
 

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he just thinks he's amazing. really. no kidding.
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That pinkish wire that looks like it was cut from the base and taped is the loop I'm talking about. I know one of my harnesses has a loop on it, too, and I left it uncut. But in all honesty, right now I can't remember if that was on my Passat or Supra.

So don't take my word on it, wait 'till I can confirm on my harness.
 

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he just thinks he's amazing. really. no kidding.
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Yup, my harness with the loop is in the Supra. I have the same three wires disconnected on my conversion harness in the Passat. The cut blue/white wire you have taped is the K-line which is correctly disconnected, and the other two seem to be a ground of sorts, both of which are unused on my Sony.

I think they're grounds, anyway. I don't have my wiring diagrams handy to check.
 

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Discussion Starter #12
PS, that wasn't a loop. I cut the pink wire back because it isn't going to anything on the factory harness.
 

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why i have the same problem, if anything just put the old hu back in or get a new aftermarket amp and do new speakers if your feeling lucky. no point in selling it. I love the car and im putting up with the problem for a few more weeks till i go home for thanksgiving and have tools. stick in there man
 

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nobody has found a clear answer to this problem. as of right now im guessing my amp is done, so i just need to save up for a new amp and speakers.
 

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I dunno about that...

My half-assed solution has been to just pull the harness to the amp every night and plug it back in- the power trip seems to turn it off, then no more dead battery.

I have no time to dig at this stupid-ass problem, but if it wasn't so cold out, I'd go screw with it right now.

What I THINK the FINAL solution will be is me running switched power to the amp- that'll teach the SOB.
 

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A friend gave me a really good suggestion for why it isn't turning off. I'm pretty sure I have some blown woofers and tweeters, and I know the amp turns on and off when it gets a signal from the speakers... sooooo could there be some interference with the blown speakers and the amp. Like a signal being put back to the amp that's keeping it on? And the unplugging is getting annoying, let alone the horrible buzz I get from the speakers when the amp does turn on, which only started when I got my new hu(could the new head unit have ruined my amp? thought that as i was writing this)
 

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remember, the amp normally gets turned on by sensing a SIGNAL from the headunit. in this case, signal means MUSIC.
 

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i understand that, but just asking if a blown speaker could cause interfierence making the amp think there is music? If not then wouldn't that mean the amp is broken if the wiring is good?
 
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