All this talk about bad alternators makes me nervous about jumping other vehicles. Is there a SAFE way to do it? 

I just hook them up. Just be sure of polarity. That is the only mistake that will wipe out an alternator. The other question are you needing a jump start or are you giving jumps to others?

I am primarily asking about jumping others.

Myself...

If I'm jumping others I woud start with the RED leads and hook my positives up on both vehicles. Then hook up both BLACK lead on my negatives or make my last connection to the ngine block of the dead vehicle. I would set my 6 CYL high idle mode. Then sit back and wait at least 5 minutes minimum for the high idle to charge the dead vehicle a bit before telling the driver to try starting. Once started I reverse out of my set up taking my grounds first then my positives.

This way you never have a point of arcing cables. Watch for a lot of GM/Chevy vehicles have stupid side post. Usually, they will have a POS connector under an RED plastic cover for jump starting.

That's one thing I've never done yet for my truck. Is having to jump start my truck. I've NEVER had a dead battery!

I made quick connects front and back out of heaviest jumper cables I found, especially for the back, that way if I got to jump someone, first I hook their battery up and then plug it in to my truck, plug only plugs in one way. I also use high idle like Mike. This also allows me to plug my winch in on the trailer or jump someone one the road facing same direction. 

I love to watch those who hook up to the first vehicle and then try to arc weld the clamps together on the other end by intentionally touching them together just to see if its live or not.

14 minutes ago, Wild and Free said:

I love to watch those who hook up to the first vehicle and then try to arc weld the clamps together on the other end by intentionally touching them together just to see if its live or not.

I used to be one of those 

Another piece of safety advice is if one of the batteries is all corroded and wet looking there is a possibility of an explosive situation if causing sparks there, always hook the cables to that battery first and remove last to lessen the chance of sparks igniting the vapors. Not too bad with the newer maintenance free batteries anymore but still see it on occasion.

2 hours ago, Wild and Free said:

Another piece of safety advice is if one of the batteries is all corroded and wet looking there is a possibility of an explosive situation if causing sparks there, always hook the cables to that battery first and remove last to lessen the chance of sparks igniting the vapors. Not too bad with the newer maintenance free batteries anymore but still see it on occasion.

In those cases, I like to hook the ground last to the block or frame metal on the other vehicle.

Yep I meant to post that as well but on newer vehicles that is near impossible although I do see some that have an actual grounding spot built into an area like the alternator bracket ect but not too common.

Some vehicles have a RED positive post for jumping from and others have the grounding spot that you mention. Some vehicles you really can't even reach the battery because of all the brackets or location of the battery.

The ones that annoy me like our Jetta has a battery with the posts inset below the surface of the battery due to the battery blankets they use now too. One can not fit most of the bigger jumper cable clamps onto the posts anymore due to being sunk into the battery.

I hate to say it, but you would want a smaller set of jumper cables for the vehicle.

One thing I've always done is to solder the jumper cables to the jumper clamps, there's no resistance and good AMP flow. Use rosin core solder. 

To throw it out there, the reason for connecting the negative lead somewhere other than the battery is so that there is more resistance forcing the electrcity from the jumping vehicle through the starter.

Electricity takes the course of least resistance, positive lead on battery and Negative, preferably on engine, creates a longer path causing more resistance.

This in turn makes the starter part of the circuit.

You don't need to worry about the AC noise when jumping other vehicles and they don't make jumper cables with diodes.

I have been thinking of inserting diodes in the PCM, ECM and the VP44 power circuits to eliminate the possibility of AC noise. Essentially a diode only allows the current to flow in one direction eliminating the possibility of AC contamination.

One that I am considering is a solar panel diode that is rated for the full capacity of a string of PV Cells to eliminate damaging the array.

Here is what I am talking about. They seem perfect to protect our trucks with an easy install.

http://www.ebay.com/itm/1600V-Volt-100A-Amp-Wind-Turbine-Generator-Solar-Panel-PV-Stud-Blocking-Diode-/201025568109

2 hours ago, eddielee said:

To throw it out there, the reason for connecting the negative lead somewhere other than the battery is so that there is more resistance forcing the electrcity from the jumping vehicle through the starter.

 

The last connection to the engine block, intake/exhaust manifold, bracket of the vehicle with the dead battery with the negative cable is two fold.

Most vehicles have their battery under the hood and batteries produce the flammable/explosive hydrogen gas. There is less of a chance of an explosion if the spark produced when attaching the negative cable to the block than the battery.  I've seen a battery blow up only once  when a fellow worker jumped it. I made sure I did it right from then on.

The starter motor is grounded to the engine block by its mating surface and mounting bolts.  When attaching the negative cable to the engine block the dead battery grounding cable and any resistance it may have is  eliminated.  Now I use a jumper box with an on/off switch and I still attach the negative cable to the engine block.

 

When all this fails the most is when the battery cables on the dead vehicle are junk. Then dead vehicle is leaning on the jumper cables more than the battery. Lot of times those are the ones with fresh battery but still having starting issues. Most likely because they can't charge the battery very well nor deliver the amps needed to turn the engine over.

Edited January 1, 20169 yr by Mopar1973Man

Someone said something about touching the jumper cables together and Mopar Man said something about reversing the cables, then I read this on Larrry B's alternator diode bridge:

Rarely does the diode pack fail unless while jumping the battery with jumper cables someone accidentally crossed the cables. (not you of course :)) or allowed the cables to touch each other or ground while the motor is running. This will toast the diode bridge.