Jump starting

waste an alternator and who knows what else.

car, but when it comes time to crank the dead car, shut the donor car off.

Same here...it's worked fine for me that way.

waste an alternator and who knows what else.

car, but when it comes time to crank the dead car, shut the donor car off.

It's also what the VW owner's manual says to do, so I'd be very curious to hear why this is possibly harmful.

dv

Don't crank the dead car while the donor car is running; this is a great way to waste an alternator and who knows what else. It's fine for the donor to be running while connected and charging the dead car, but when it comes time to crank the dead car, shut the donor car off.

--TW Voice of experiences.

Alternators are not made to be operated at the high end their output for extended periods of time. Charging a dead battery can load an alternator significantly, which increases it's operating temperature (which on most vehicles decreases output voltage). The added draw of the starter, particularly during periods of long cranking, can overheat the alternator leading to failure. I worked in the auto salvage business and fried enough alternators (semi-intentionally) to say it's better safe than sorry.

--TW I don't care.

Should I follow the advice of VW or ignore it and follow that of some guy on a NG... with 'years of experience?' Hmmmm, lemme think about that one.

I've boosted 10's of cars over the years with the other car running and never blown an alternator. I have heard of ECU's blowing in rare cases but never alternator's.

Don't crank the dead car while the donor car is running; this is a great way to waste an alternator and who knows what else. It's fine for the donor to be running while connected and charging the dead car, but when it comes time to crank the dead car, shut the donor car off.

--TW Voice of experiences.

Call me back when you hit numbers in the three digit range.

--TW

Oh, yeah, I always seem to forget that the Germans are perfect, cars never break, engineers are always right and real world experience is not worth anything.

--TW If caution is the flick of a switch, is it worth it?

Jim B.

Time for a poll. Surely our combined experiences of boosting with the donor car running outnumber the 100s that Tundra seems to have done. Lol.

I've done about 40.

I've also jumped many a car with the engine running and have never blown the alternator. But what he says does make some sense. I guarantee that everyone of us that say that you don't need to shut off the engine, will blow their alternator the very next time they jump someone. There is a whole lot of karma involved with VW's.

Steve

Tell you what. I'll do it my way, you do it your way. Good luck.

--TW Do you use a wrist strap or anti-static mat while working on electronics?

Agreed.

I wear rubber boots around my house although I do have a green ground wire running off the cold water inlet in the basement to every room in the house. I ground-out, as it were, before entering any room with sensitive equipment. When boosting, I connect -ve to -ve terminal and jumper the +ve terminals with wet hands. Rubber boots and cold water supply ground (just in case) have saved me countless times, but that's another story.

Working on it being winter and all.