quote:

Originally posted by Chris42:
There are jumping terminals under the hood of my Touareg (2015 model) put specifically there for jumping cables. Not sure about the Tiguan. In my case the battery is under the drivers seat! While I like knowing where the basic components are for all my vehicles, I have yet to see this battery.

A call to the service department will tell you whether you can jump start the vehicle. Then again, that inch thick manual in the glove box might tell you too.

Lol, I thought Jeep was the only one. My poor neighbor spent half an hour looking for his battery in his wife's new Jeep a few years ago and asked me if I could come over to help. We eventually figured it out...under the damn front passenger seat. WTF.

Anush, there may be some truth to the don’t jumpstart it...when I was a cop they told us not to jumpstart other cars or get our cars jumpstarted without disconnecting all the computers and gizmos installed. One of my coworkers burned up a radar unit and a laptop one afternoon jump starting his car in the driveway.

quote:

Originally posted by MikeinNC:
Anush, there may be some truth to the don’t jumpstart it...when I was a cop they told us not to jumpstart other cars or get our cars jumpstarted without disconnecting all the computers and gizmos installed. One of my coworkers burned up a radar unit and a laptop one afternoon jump starting his car in the driveway.

That's why you should connect the negative cable from the donor battery to a ground somewhere in the engine compartment of the dead battery and not to the battery's negative terminal.

I thought the reason for connecting the negative cable to a ground away from the weak battery was to avoid causing a spark near the battery where hydrogen gas may build up as a part of the charging process.

quote:

Originally posted by Anush:
No, the dash goes nuts again & security alarm goes off. I call the dealership & service tells me that the electronics will not allow my car to be jump started.

As far back as 1997, cars became equipped with their own power supply and/or multiplexer. It takes the 9.6 - 14.4 volts available from the electrical system (depending on load) and gives a stable voltage output (5.5v, 10v, 12v, etc... to keep a clean input signal. This is especially true if your Tiguan has a multiplexer as most new cars do.

The jump starter may have a power output higher than what the power supply allows, or may be incompatible if your ride has a 24v or 48v nominal voltage. Jumping the low battery with a second battery or from another car without the engine running may be the way to go.

One thing of note: many German cars as well as others have a fuse in the power distribution module that is pulled out so the battery doesn't drain during shipment to the dealer. This fuse can also be pulled out if you are parking for an extended time (airport, etc...) up to thirty days.

Last week I had to get a new battery in my brother in laws Jag. He’s gone for several months so I keep an eye on things, including occasionally driving the car.

AAA guy came out and tested the old and installed a new battery. The Jag battery is in the trunk and I was pleasantly surprised how clean it was. Of course since it’s not under the hood and open to the environment it stays spotless. BTW a Jag battery is different shape than you’d expect, more longish then typical.

To answer Edmonds question above, my 15+ years career in Automotive Service Management taught me that more batteries seemed to die in the summer heat than the cold winters, by a small but definite margin.

You get what you pay for in jumper cable quality. BTW if you want really good jumper cables you can go to a welding supply store. They’ll sell you whatever length you want of welding cable and some super heavy duty clamps. If you’re really nice to them they might even install the clamps for you. Let them, they are really good and know how to get the clamps on tight, they’ll never loosen up.

I’m reminded of the old saying: If it has Tires, Tits or Transistors it’s Troubles, but it’s great when everything works.

EDIT: While in the trunk watching the AAA guy replacing the battery I noticed the spare tire was flat. Out of sight, out of mind, but don’t forget to check your spare tire pressure occasionally.

quote:

Originally posted by trapper189:
I thought the reason for connecting the negative cable to a ground away from the weak battery was to avoid causing a spark near the battery where hydrogen gas may build up as a part of the charging process.

No. It's to help prevent harming sensitive electronics.

What protects the sensitive electronics when you install a new battery?

How do the electronics know where you've connected the jumper cable?

quote:

Originally posted by Balzé Halzé:

quote:

Originally posted by trapper189:
I thought the reason for connecting the negative cable to a ground away from the weak battery was to avoid causing a spark near the battery where hydrogen gas may build up as a part of the charging process.

No. It's to help prevent harming sensitive electronics.

That and connecting the negative cable to an engine ground would have the voltage draw directly to the starter in the event of a defective grounding strap, loose/corroded negative cable, etc...

But yes, The primary reason to connect the negative cable away from the battery was to avoid causing a spark near the battery where hydrogen gas may build up as a part of the charging process as trapper189 suggested. This was the primary reason even back in the days of external voltage regulators and six volt systems.

quote:

Originally posted by trapper189:
What protects the sensitive electronics when you install a new battery?

How do the electronics know where you've connected the jumper cable?

Some vehicles have a spring loaded switch underneath the battery to discharge the electronics when the battery is removed from the tray. Starting a car with a higher voltage output than normal has always let problems arise. Fries points when the ignition switch has bypassed the ballast resistor on the coil back in the day.

quote:

Originally posted by trapper189:
What protects the sensitive electronics when you install a new battery?

How do the electronics know where you've connected the jumper cable?

Man, I don't know. I only work here.

But in all seriousness, it would seem that I was wrong.

The parts store I use (Advance) has a small battery they plug into the OBD port before they disconnect the old battery to maintain voltage to the car / computers during the swap.

Connecting the ground last and away from the battery is indeed done at least partly to prevent the spark from igniting the battery gasses.

From about 20 feet away I saw a coworker get drenched in battery acid, face arms neck and chest, when his battery exploded as he attached the cable and it sparked.
Sounded as loud as a shotgun blast.
Luckily no one was impaled with any of the shrapnel from the plastic battery case and his eyes were protected by his glasses.

He stripped to his drawers and we turned a hose on him and washed him down. His ears rang for a while. The acid rusted the bottom side of his hood because in the excitement of the event we forgot to hose it off.

I picked up a Solar BA9 digital battery and charge system tester a couple years ago, and it's been really handy to have around. It tests capacitance to tell you the state of health and state of charge of a given battery. I used it last week when my Dad's Toyota wouldn't start. He had just returned from running an errand a few hours earlier, but the BA9 indicated only 6V and a "bad" state of health for the 4 year old battery. That told me it was an internal short, so no wasted time trying to charge a bad battery. A quick replacement and he was back in business.

Solar BA9

It can be tough to access a good ground on a lot of these newer cars with all the plastic shrouds covering the top of the engine. Also not all battery jumpers are created equal, amperage can range from about 400 amps to 1700 amps, nor as mentioned are jumper cables. I had a cheaper set of jumper cables arc between the handles on the positive and negative clamps on one end creating a dead short, and nearly causing a fire.

quote:

Originally posted by trapper189:

quote:

Originally posted by V-Tail:
very likely true, but has nothing to do with the question that Anush asked.

Has everything to do with the question asked. A completely dead battery won't store any electricity and the gauge of his jumper cables is likely too small to allow enough current through.

After scratching my head, thinking about it, and going back to re-read things, it appears that we are talking about two different questions: Apparently, you were referring to the question in the thread title, "Why can't I jump start my VW Tiguan?" and I was referring to the question in the first post of the thread, "Was he [the dealer] just BS'ing me?"

So, we're both correct. Or maybe we're both wrong.

Guess the best way to know for sure would be to check the owners manual (or shop manual if available).
Mine has an all caps warning in bold type that reads:

Jump Starting
Standard procedure - Jump starting
Warning: Review all safety precautions and warning in the battery, starting system, and charging system sections.
Do not jump start a frozen battery, personal injury can result.
Do not jump start when battery indicator dot is yellow or bright color.
Do not allow jumper cable clamps to touch each other when connected to a booster source.
Do not use open flame near battery. Remove metallic jewelry worn on hands or wrists to avoid injury by accidental arching of battery current.
When using a high output boosting device, do not allow battery voltage to exceed 16 volts. Refer to instructions provided with device being used.

This will specify the order and what connections to make if the battery is not in a location that you can get the cables to.

Sorry for the jumbo pic.

@V-Tail

I was scratching my head and looking for the hidden camera. Now that I see the ambiguity in the title question and the context of the post, I missed Anush's point and you were right.

Another reason to jump the ground to something besides the battery is that it eliminates a bad ground cable or ground connections.

My jumper cables were purchased out of a pile of crap at a jeep parts swap meet. Ugly things, back in the 1980s. They're still ugly. But they're made from 0000 welding lead. Heavy to carry very far, but they really work. This reminds me to go dig them out and check the clamps for corrosion so they work when or if I need them. The advantage of heavy and long cables is you can almost always get close enough to make connections.

On to VeeWees:

We had a then new 2003 Passat W8, the equivalent of a V8 engine. It had a drain problem. All was well if you drove it daily. But if you left it sit, it would drain the battery. At the dealers I wasn't a nice guy. I made the point I'd bought a new, top of the line car that couldn't be depended on to start. Kind of embarrassing when you were with others, wanted to take you new, kind of high dollar car and it was dead. I suggested 2 approaches to the dealer. One was that they give me one of the solar chargers they install in beetles.

The dealer had a different suggestion, but agreed mine might work until they could come and get my dead car. So they flat bedded it back to the mother ship. Then had one of their experts go over the entire car to figure out what was alive that shouldn't be. He found it, fixed it and then the dealer installed a brand new battery, problem solved.

We still have my wifes EOS, bought new in 2007. Its still got its original batteries. For whatever reason they installed 2 x 6v in the trunk. No, I don't know why but we sure have gotten our money's worth out of them. New ones will cost a cool $4++. At this point I don't care, I'll pay it with a smile.

Just to add another opinion, some newer cars the computer will shut down when the flow of electricity is interrupted. So when you have a dead battery or disconnect the cables to clean the battery the computer shuts down and the vehicle won't start. To reboot use you key to lock then unlock the driver door. Lock unlock, about as fast as you can say it. The computer is now up and running, as your vehicle should be.
BTW I learned this after I cleaned the car battery, car wouldn't start, and had the car towed to the shop.

Is this VW started yet or what OP!?

dash lights to go blinking nuts

This might seem crazy but you likely have a bad alternator. Don't know why but a faulty alternator and jumper will create this situation. Check battery voltage engine off and with engine running.

quote:

Originally posted by Anush:
Yesterday, my Tiguan would not start. It is a 2016 AWD base model with 12,000 miles (Yes I am retired & the grocery stores are only 2 miles away). OK, I had no prior symptoms of a declining battery but it would not begin to turn over. Out comes my battery jump starter that had no problem jumping my V8 Touareg. Nothing, as it only caused the dash lights to go blinking nuts. OK, out comes the charger but after 5 minutes it shows fully charged. Now, in my past 60 years of auto & motorcycle experience I should be able to turn the starter over with the charger hooked up to the battery. No, the dash goes nuts again & security alarm goes off. I call the dealership & service tells me that the electronics will not allow my car to be jump started. I never heard of such a thing. Was he just BS'ing me?

quote:

Originally posted by DonDraper:
Is this VW started yet or what OP!?

1st page, 13th post he states he replaced the battery the day before his OP. Including that bit of info in the OP would have been good.