2nd Gen Non-Engine/Transmission Jump starting question

[tbrudder]

Just something that popped into my head today--what is the correct way to jump someone's car off, these days?



All my previous cars were a lot simpler, electronically, so I kept the engine running while trying to jump the other guy off, to keep my battery from getting drained.



Recently, though, I've been told this is bad for the various computers. The owner's manual in my '99 isn't very helpful--it tells how to hook it up to a starter battery if _your_ battery is dead, but not the other guy's.



So what are you guys doing?



--Ty

 

[lmills]

I typically do the positive cable on the good battery then to the dead battery. Then I do the negative to the good battery and hook the other end to the block of the dead vehicle.

 

[clong]

Turn your engine off. Hook up cables. Start vehicle that has the good battery. Allow to charge for a minute or two then start dead vehicle. Remove cables. The voltage spike of hooking a dead battery up to your truck with the engine running can kill the alternator and/or other electronics.

 

[AKAMAC]

Let your alt. charge the other system for about 4 min. at 1400 RPM and when they start the load will be on their battery, no problems.

 

[y-knot]

Well my answer isn't going to be very popular, but I do not jump start anyone anymore. I have only broken that rule once or twice, when I new a co-worker didn't have an electrical problem only left his lights on. The problem now days is the ever increasing dependence on electronics, and computer systems to run the vehicle. These systems are very, very sensitive to current fluctuations, voltage spikes, stray signals (noise), and magnetic Fields. It is very possible to jump off someones car that has an electrical problem (which is usually why they are needing a jump), and damage or "fry" your system. Particularly cars that have alternator problems. Our trucks depend on the PCM to regulate the voltage, try replacing that after a "nice" jump start. The PCM isn't the only "computer" on the truck, just the one that is usually effected. People don't realize the dangers because they can not see it, but it exist. I deal with "electrical noise" all the time, governments recognize it, we us chokes, capacitors, ect to "filter out " certain "noises". Computers operate at very, very high frequencies, this is necessary for there function. But because of this, they allow these frequencies to escape into the electrical wires that serve them. It is very possible, and happens all the time, to simply plug into a circuit that is also serving a computer, and be able to "read" what the computer is doing. This is a major security breach that large companies, government offices, ect. address every day, but few people no about it. Anyway, these same principles are at work when you electrically connect your truck to someone else's vehicle, they can and do pass thru the jumper wires. So be carefull when you would like to be nice and jump someone off, it might end up costing you

 

[Koa Man]

I carry around one of those battery/compressor/light combos from Costo. Cost about $60 and I have jump started my truck and other cars with it. My wife's Lexus owner's manual does not recommend jump starting the vehicle. It says to get another battery and install it. In any case, it is wise to check the jump starting procedure recommended in the vehicle's owner's manual. Some have weird procedures you must do, like making sure the driver door is kept open, etc.

 

[jeepit]

I did the same as koa man. I purchased a battery jump starter box. It is easier to use and safer. It has paid for itself. This reminds me to charge it today!

 

[MCummings]

With two 900amp batteries under the hood,, I just pull up, shut my truck off, pop the hood,, connect the cables, let them start there vehicle, disconnect the cables, and re-start my truck, and be on my way.



1800amps will get just about anything started out there.



Merrick Cummings Jr

 

[D6Diesel]

With the engine off, the PCM could not be damaged as per y-knot's concern?

 

[tbrudder]

Originally posted by D6Diesel

With the engine off, the PCM could not be damaged as per y-knot's concern?

Anyone care to comment?

I'm curious about this point, too.



--Ty