# Jump Start Connections



## cai (Mar 22, 2009)

I have looked in the FAQ listings, but did not find an answer to the following.

I was in need of jump starting one of my cars yesterday and I tried to use the Phaeton. I looked under the hood and saw a + connection under a red shroud. I was unable to start my other car.

Today, while thinking about it, I realized that somewhere in this forum I had read that this + connector cannot be used for this purpose. I wonder:

1- For what can this + connection be used?
2- How does one jump start another vehicle using the Phaeton as a source?
3- What connectors does one use to jump start a Phaeton in case of an emergency?
4- Would using the left hand side battery for jump starting another vehicle or for jump starting the Phaeton cause any damage to the Phaeton?
5- Can the car be trickle charged through this + connector.

As always your comments are appreciated.

Thank you, 

cai


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## Victor R (Jan 7, 2010)

Ironically, I just ran into a situation where I needed to jump start a Cadillac Deville which I had parked next to one of my Phaetons in the garage. I only briefly considered using the Phaeton for this but quickly decided against it because of the two batteries and complicated arrangement.

I wound up starting the Caddy using my wife's 2002 BMW. Neither of the two cars has the battery under the hood, but they both have a + connector - the one for the Caddy is red; the one for the BMW is black but the manual had good instructions (the Caddy manual was worthless).

After a successful start and return from the GMC dealership's shop, I searched the Phaeton forum, and was rewarded by finding *this thread*.

cai - many (but not all) of your questions are answered there. Maybe my post, though, will spur some of our more mechanic-inclined members to elaborate, as I, too, am interested in more detailed answers to your questions.

Victor


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## jyoung8607 (Feb 14, 2006)

I think some of the information in that old jump-starting thread may not be right. The forum has collectively developed some additional understanding of the Phaeton's electrical system since then.

I would avoid jump starting using the VPS electrical system, in either direction (Phaeton as supply or Phaeton as dead vehicle). Lots of reasons there which I can get into if you really want to know, and VW tells you not to. You should use the start-dedicated side of the electrical system, either directly to/from the battery itself or using the terminals under the hood.

Junction TV2 under the hood - the jump starting positive terminal - theoretically should be up to the task of supplying jump current to another vehicle just as well as it can receive it. I am only slightly over-simplifying things when I say TV2 _is_ the far end of the starter battery positive cable. There would be a tiny bit of voltage drop, but it's an enormously thick cable and the limiting factor is generally going to be your jumper cables and the quality of contact at either side.

Some people seem to have trouble using that terminal. I think there are two categories of problems:



You can't use it to maintain or support the VPS side of the electrical system. This is really an education thing, not a problem. When owners or mechanics need to hook up a battery charger or maintainer, the VPS side is usually what they want to support. The starting side is isolated from the VPS side unless the battery monitoring controller decides otherwise at startup, and even then only for a few seconds upon an actual start attempt.
Poor negative contact. I'm not sure if everyone's car is like this, but here's something I noticed on mine: the TV2 positive terminal lug is bare metal, but the negative terminal lug is painted along with the rest of the firewall. I found that incomprehensible. You need solid positive AND negative contact, and contact to the painted negative terminal will be extremely poor at best. *[edit: it turns out there's a cap you have to remove ]* I'm not sure what the V8 looks like, but on the W12 with the engine covers on, there's not any other good options for a ground clamp.

Summary: You're supposed to be able to jump from the starter side using the terminals near the engine. In reality you might have to jump directly to/from the starter battery. Avoid the VPS side of the system entirely.

Jason


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## n968412L (Apr 23, 2009)

jyoung8607 said:


> I think some of the information in that old jump-starting thread may not be right. The forum has collectively developed some additional understanding of the Phaeton's electrical system since then.


I think Jason is right - there's been quite a lot of learning in the last year or so about some of these aspects - I think with magasterial research done by Willem Bal.

For jump starting at home I use the old AGM battery that used to be the convenience battery in my GP0. For jump starting away from home... well... I never have yet!


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## PanEuropean (Nov 3, 2001)

Good points made by all. I have appended a reference onto that original thread directing readers to this newer discussion, which presents additional information we were not aware of back in 2006.

Michael


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## invisiblewave (Sep 22, 2008)

Is there a jargon translation thread somewhere? I have no idea what VPS is.


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## n968412L (Apr 23, 2009)

invisiblewave said:


> Is there a jargon translation thread somewhere? I have no idea what VPS is.


Vehicle Power Supply? Just guessing... I mentally translated it as "convenience"....


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## Paximus (Aug 26, 2011)

Jason introduced the term VPS (vehicle power supply) as a useful acronym to describe the Onboard Power Supply referred to by VW in SSP 272.

Bentley Motors translate the term as the supply for the vehicle Systems as opposed to the supply for the Starter motor.

I suspect that the term _Onboard _has a more generic use in German than it does in British English, where it usually refers to the state of having been raised onto a boat or bus.

The button on my central display screen labelled BOARD-PC was a puzzle until I pressed it and discovered it's the trip screen, not a Board for a PC. I still don't know what the PC stands for, the trip screen is hardly 'personal'.

Chris


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## Itzmann (Jan 16, 2006)

Two items:

1) I used the Phaeton to jump-start one of our other cars, once. I followed the instruction manual. Phaeton still runs, although mind you, two computers have been replaced at various times since, apparently for unrelated reasons (Kessy computer and air conditioner computer).

2) Since my failure to jump-start the Touareg (melted cables, fire, and again melted *very thick, most expensive* cables), I purchased a $90 jump-start, portable device –essentially an easy to handle portable battery with cables and some ancillary functions.

I cannot recommend this $90 device too much. First, there is no risk of damaging any expensive electronics on our cars. Second, it is so much easier to actually jump-start because there is no need to reposition any vehicles. Third, no spark at all because of the device's hefty on-off switch.

The one car I've never had to jump-start is the Phaeton.


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## invisiblewave (Sep 22, 2008)

I second the battery pack recommendation. Mine recently stopped taking a charge but I'll be buying another as soon as I can swallow my principles and take a trip to Walmart.

I can also highly recommend Michelin (and probably other brands too) smart jumper cables. It doesn't matter which way round you attach the cables, the cable itself figures it out. They're even smart enough for the old ball & chain to get it right, as I found out a couple of weeks ago!


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## Paximus (Aug 26, 2011)

Those portable starter units are a really practical idea.

For what it's worth, here is Bentley Motors' procedure for safely jump starting a Flying Spur without using the under-hood terminals (do they exist on a FS? - the extract below says it is "extremely unlikely" to need to jump the platform!).

They say to put the donor battery plus lead on the Starter (RH) battery +ve post and the minus lead on the Systems battery (LH) -ve post. I suppose that's a safer way of doing it.

I have never seen a VW document instructing how to do it.

Chris











(c) Bentley Motors, use for private research only


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## jyoung8607 (Feb 14, 2006)

invisiblewave said:


> Is there a jargon translation thread somewhere? I have no idea what VPS is.


Sorry for the jargon. Yes, as others mentioned, I meant vehicle power supply. I don't think I can take credit for coining that one; it seems to be in common use elsewhere on the forum. But, I might be the only one using an acronym. Typing it out over and over gets old. 



n968412L said:


> I think Jason is right - there's been quite a lot of learning in the last year or so about some of these aspects - I think with magasterial research done by Willem Bal.


Seconded on Willem's contribution. He's the one that clued us in to the official wiring diagram identifier for the two main firewall crossing points. He took some good pictures over on this thread when he was troubleshooting low-voltage issues. He was mainly concerned about TV22, which is on the VPS side, but TV2 for the starting side is right next to it. It's the one on the left, the one that has an exposed post on top for a jumper cable clamp.

Note the grounding post that Willem identifies. I have that post, but the stupid thing is painted, so electrical contact quality is somewhere between crap and zero. I can't see for sure, but I think Willem's is bare metal or at least has been sanded down. I'd be curious to know what other owners have, bare metal or painted. You can take a look just by removing that one tiny cover with no tools needed.

Photo borrowed from Willem's thread:










Jason


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## n968412L (Apr 23, 2009)

jyoung8607;81281593-Using-VCDS&p=77025506&viewfull=1#post77025506" said:


> Note the grounding post that Willem identifies. I have that post, but the stupid thing is painted, so electrical contact quality is somewhere between crap and zero. I can't see for sure, but I think Willem's is bare metal or at least has been sanded down. I'd be curious to know what other owners have, bare metal or painted. You can take a look just by removing that one tiny cover with no tools needed.


Jason - I've just been to have a good luck at the negative post connector under the bonnet. You can't see it clearly in Willem's pictures - but I think mine (both of mine actually) is the same as his. Initially I thought it was a metal stud... painted. But it looks like it's a set screw that is completely covered with a plastic cylindrical shroud. The shroud pulls off... or screws off.. it's a tight fit. And underneath is a set screw... or a threaded stud... which you can just see in Willem's pictures. The surface seems to be anodized or possibly galvanized.

I'm not sure I'd have worked it out on a dark night.... 

M


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## jyoung8607 (Feb 14, 2006)

n968412L said:


> Jason - I've just been to have a good luck at the negative post connector under the bonnet. You can't see it clearly in Willem's pictures - but I think mine (both of mine actually) is the same as his. Initially I thought it was a metal stud... painted. But it looks like it's a set screw that is completely covered with a plastic cylindrical shroud. The shroud pulls off... or screws off.. it's a tight fit. And underneath is a set screw... or a threaded stud... which you can just see in Willem's pictures. The surface seems to be anodized or possibly galvanized.
> 
> I'm not sure I'd have worked it out on a dark night....
> 
> M


Just walked outside to check this on my car.

:banghead: :banghead: :banghead: :banghead:

Well spotted. :beer: User error on my part. That's exactly it, there's a plastic cover over the real terminal.

Jason


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## n968412L (Apr 23, 2009)

jyoung8607 said:


> Just walked outside to check this on my car.
> 
> :banghead: :banghead: :banghead: :banghead:
> 
> ...


Don't beat yourself up too much... if I didn't have two Phaeton's I wouldn't have twigged. I looked at one and thought it was a painted metal post... I thought then I'll check that the other is the same... and in looking and trying to work out if it was painted I realized that it wasn't cold enough to be steel (as it's freezing here....) - so that's when I twigged it was a plastic cover....


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## invisiblewave (Sep 22, 2008)

So to jump start it, or to jump start another vehicle, you'd use the jump start post and the ground point from that picture?


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## Victor R (Jan 7, 2010)

That is how it works for other cars that have the battery located elsewhere than under the hood. It appears an industry standard. Jason's comment:


> I am only slightly over-simplifying things when I say TV2 is the far end of the starter battery positive cable.


makes all the sense in the world with the Phaeton being no different in this regard than other cars.

Victor


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## cai (Mar 22, 2009)

Let me recapitulate on what I have learned from the answers here:

1- For what can this + connection be used? 
*Exclusively for jump starting the Phaeton, nothing else.

2- How does one jump start another vehicle using the Phaeton as a source?
*Not sure yet. Does one use the left side battery or right side battery - no acronyms or part numbers please.

3- What connectors does one use to jump start a Phaeton in case of an emergency?
*The under the hood connectors, as very nicely shown in the threads.

4- Would using the left hand side battery for jump starting another vehicle or for jump starting the Phaeton cause any damage to the Phaeton?
*See #2 above.

5- Can the car be trickle charged through this + connector.
*No. But, I do not yet have a clear answer as to which side battery to use for trickle charging the car during long periods of non-use. 

I do not think that I have ever seen the right side battery. The left side one has a very accessible panel; the right hand side battery ..... I just looked at it and do not see an easy way to get to it.

Thank you,

cai


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## n968412L (Apr 23, 2009)

1 - I'm not sure. I don't think I've seen anything to suggest that this post can't be used in either direction.

2 - RH Battery - and make the connexions from the battery directly in the boot, not the posts under the bonnet.

3 - yes

4 - Not definitively - but it has some risks and is bad practice. And harder to do anyway given the difficulty of access to its terminals.

5 - trickle charge the LH battery. I think the car electronics will float the RH battery from it. In any event - apart from on the V10 - the LH battery is the better battery and will definitely start the car if charged, even if the RH battery is dead. It is important to keep the volts up on the LH battery.. so charge this one - and charge it directly on its terminals - ie in the LH side of the boot.

The RH battery is much more difficult to get at. The cover/cubbyhole is only held in by spring clips.... but they are STRONG. You need to get a good grip around the extremities of the cubbyhole. I broke one of mine and had to glue it together again.. but that's because I included the metal bar and the fishnet in what I got hold of. Won't do that again!

Hope (a) this helps and (b) it doesn't contradict anyone else's understanding!

Regards

M


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## Victor R (Jan 7, 2010)

With my current understanding, I would think that the terminals under the hood can be used to both jump start a Phaeton and to use the Phaeton as the vehicle to jump start another. That is how all other cars with a + terminal but no battery under the hood work. If, as noted, the + terminal essentially connects to the + side of the starter battery, there is no reason that the Phaeton is any different. This arrangement takes the LHS battery out of the equation.

Victor


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## DmcL (Sep 30, 2012)

have been jump starting my 89 325i from the left battery with no problems.. cover comes off easier on the left side so thats where i have been jumping from. have jump started the 325i atleast 6-7 times so far, its not being driven and sits for weeks on end between blowing out the cobwebs for 15-20 mins every so often.


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## n968412L (Apr 23, 2009)

DmcL said:


> have been jump starting my 89 325i from the left battery with no problems.. cover comes off easier on the left side so thats where i have been jumping from. have jump started the 325i atleast 6-7 times so far, its not being driven and sits for weeks on end between blowing out the cobwebs for 15-20 mins every so often.


Good to know. I'd probably not do it for preference... but this clearly shows it's not a high risk thing to do! As a matter of interest does your P have a RH battery? There's a rumour that some 3.2 V6s only have a LH battery - but I think everyone who's ever seen one and posted here has always had a RH one too.


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## cai (Mar 22, 2009)

Thank you for the comments and clarifications. I am now better informed as to what to do when I run into a jump start situation, be it my car or someone's else.

cai


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## bilmac (Oct 10, 2012)

DmcL said:


> have been jump starting my 89 325i from the left battery with no problems.. cover comes off easier on the left side so thats where i have been jumping from. have jump started the 325i atleast 6-7 times so far, its not being driven and sits for weeks on end between blowing out the cobwebs for 15-20 mins every so often.


As you have the petrol engine with only 1 battery its not the same thing, or is it?


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## bilmac (Oct 10, 2012)

bilmac said:


> As you have the petrol engine with only 1 battery its not the same thing, or is it?


Sorry I had not seen Mike,s (n968412L) post. I did think all petrol had only 1 battery. bilmac


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## bilmac (Oct 10, 2012)

bilmac said:


> Sorry I had not seen Mike,s (n968412L) post. I did think all petrol had only 1 battery. bilmac


I am a dope. W12 phaetons are petrol. I meant cars with 3.2 petrol engine. Bilmac


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