Jump starting another person's car.....

I've always heard, when you jump start someone else's car, let it charge for a while then remove your the positive side of your cables before allowing the other person to crank it over. Is this true? ...something about blowing your diodes out. I know diodes only let current flow one way........does voltage try to travel back to the other alternator..........so the person with the larger diodes (did i say that?) wins?

When I normally jump someone, I follow this advice..... About two years ago, I jumped a fella and didn't do this.....I was in a hurry. Well, a week later, I replaced my alternator....

Snopes.com didn't have anything on this

 

I've always just left the two connected, and I've never had alternator problems.

 

Well around here this time of the year we do a fair amount of this. I've never removed a jumper cable until it's started. I believe you only have trouble with diodes if you reverse your cables. I do however attach the positive to the dead battery and then attach the negative to a good engine ground. When it starts I remove the negative first so that if I draw a spark it's away from potential explosive g***es from the battery. lol

 

rustlers right on with his advice last connection goes to good engine ground on dead car and its the FIRST to disconnect once started.From my local 3rd generation electrical rebuilder DO NOT jump start or charge a totaly dead battery with the small gm altinator cars or you will cook the diodes.They can barely keep up to a good battery without overheating after loosing 2 altinators in a row in a week I believe him and now carry a jump pack .He asked if I was jumpstarting people with my pontiac sunbird on the second rebuild in a week

 

got a nice pair of cables in my trusty volvo.... seems I keep them there just for others. hook em up...with my car running, unhook them after the car starts... never have any sort of problems.

I've had cables in every car I've owned for the last 15 years. never had a problem... even hooked them up backwards one time.. guy had 2 red cables. no problems.

'course I've never driven one of those newfangled cars. they may be different.

 

I'm 53 been jumpstarting cars for a long time also. Worked on the service trucks for several garages/gas stations and actuallywas required to go to a seminar on proper battery service.Ive never had a problem either but was present when a kid exploded a battery in a new pontiac.the battery case hit the open hood with enough force to punch a 3 inch hole in it then landed behind the kid about 5 feet on the ground he had to be the luckiest kid going because with the explosion and acid all over everything in 10 feet he did not have 1 scratch or one bit of it on him!volvos are great cars or atleast the 60 544 my folks had was and yes the late mini alternators in GMs are marginal at best they overheat very easy

 

Another good practice is to turn on your blower motor full. The inductive circuit of the motor reduces harmful spikes. This is more critical in newer cars with gobs of electronics but I think it is still a good idea regardless. Stu