crickrichard:
I’ve never needed to jump start a truck, but i guess i would just connect negative to negative, then positive to positive, starting with the ‘donor’ vehicle.
Always connect the positive first, and disconnect the positive last.
Reason: If you accidentally drop the jump lead you’re trying to connect, it’s much more likely to hit a piece of grounded chassis than a positive connection.
If you connect negative first, and then drop the positive lead whilst you’re trying to connect it, you risk shorting out the battery on the other vehicle, which isn’t a good idea.
If you connect positive first, then the problem is eliminated.
Talking of Actros jump starting , my 55 plate has an Earth and Live sleeve type connections between the exhaust box and fuel tank , don"t even need ignition on to jump start…well thats what the mechanic said at Mercs Crawley when she went for 6 weekly inspection last week…
After 20 odd years on the road , saw a new way of jump starting couple of weeks back…live ( red ) wasn"t long enough to get to both sets of batts , so we joined red and black together , connected to both live terminals , then put a tyre lever across from front steel rim to the truck next to it steel rim and earthed her out , and Bingo , she started ! Was proper amazed !!! 
In a way you done the right thing, but possibly in not the best way.
You had a genuine reason why you couldn’t help the other lad, lets just hope he understands! I hope you don’t believe in Karma- what goes around comes around and all that.
But if you are not sure about anything like that then don’t do it. No one is going to reward you for frying your truck in an effort to help another.
If you are going to jumpstart then ficking the isolator switch should cover those eventualities… or to be sure to be sure start your lorry then disconnect the live terminal. Your lorry will still run but the electrics are safe from any surges etc.
MrFlibble:
crickrichard:
I’ve never needed to jump start a truck, but i guess i would just connect negative to negative, then positive to positive, starting with the ‘donor’ vehicle.
Always connect the positive first, and disconnect the positive last.
Reason: If you accidentally drop the jump lead you’re trying to connect, it’s much more likely to hit a piece of grounded chassis than a positive connection.
If you connect negative first, and then drop the positive lead whilst you’re trying to connect it, you risk shorting out the battery on the other vehicle, which isn’t a good idea.
If you connect positive first, then the problem is eliminated.
This is correct. This is what the Army teaches you;
“To connect be POSITIVE and to disconnect be NEGATIVE”.
EnglishTrucker:
MrFlibble:
crickrichard:
I’ve never needed to jump start a truck, but i guess i would just connect negative to negative, then positive to positive, starting with the ‘donor’ vehicle.
Always connect the positive first, and disconnect the positive last.
Reason: If you accidentally drop the jump lead you’re trying to connect, it’s much more likely to hit a piece of grounded chassis than a positive connection.
If you connect negative first, and then drop the positive lead whilst you’re trying to connect it, you risk shorting out the battery on the other vehicle, which isn’t a good idea.
If you connect positive first, then the problem is eliminated.
This is correct. This is what the Army teaches you;
“To connect be POSITIVE and to disconnect be NEGATIVE”.
thank you very much, very useful to know!
switchlogic:
Have any of you, and not your mates brothers aunt, actually had anything blow up from jumping?
Not a truck admittedly, but yes I have. There seem to be quite a few of the new Ford S-MAX’s in my area, all with the Ford Converse computer system.
When I collected my new car from the dealer, they told me NOT to ‘give’ or ‘receive’ a jump start as it will fry the Converse.
Fast forward a few months and a chap down the street needed a jump start (wife had left the lights on all day, despite the warning tone when you get out of the car!!). As he was about to get ‘jumped’ I mentioned about frying the Converse system, but no, he said it’ll be fine!
End result - his car didn’t start, his converse did fraz, his car wouldn’t start when the recovery came out to him, his car was taken to the dealer on the back of a wrecker and worst of all, the Ford warranty didn’t cover him because he had used jump leads!!! I believe the total cost to him was well over €1200!!!
JD - I’d have done the same as you. Maybe would have also asked if there was anything else (other than jumping) I could do to help i.e. lend my mobile to call for other help, but beyond that if I wasn’t sure about frazing the electrics I wouldn’t have risked it.
Did he really mean a Nacho break? 