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Jump Start
Posted: 11 Dec 2008, 10:38
by jpee
Just out of interest.
My brother called to say his Chrysler neon battery was flat. Jumped in van to go give him a jump start. Connected jump leads, but the van (1.9 water cooled petrol) wouldn't jump his car. Tried it on his transit (that battery was flat as well) no joy. Thought maybe something to do with relay to leisure battery so disconnected that still nothing. Got neighbour with his 1.4 fiesta to try, same leads, and both car and van started first turn of the key.
So, why wouldn't van jump his car or van?
Re: Jump Start
Posted: 11 Dec 2008, 12:35
by Ian Hulley
Dunno but I started my Father-in-Law's JCB with ours

Re: Jump Start
Posted: 11 Dec 2008, 13:18
by tonytech
I've jump started many cars with the van.
Can only think a poor connection or poor battery condition in your van.
T
Re: Jump Start
Posted: 11 Dec 2008, 13:36
by jpee
Bit of a strange one. Lead connections were fine and my battery in tip top condition. Hey ho one of those wee quirks that keep things interesting.
Re: Jump Start
Posted: 11 Dec 2008, 17:16
by funbus1
I Jumpstart my van from my leasure batt

Re: Jump Start
Posted: 12 Dec 2008, 22:14
by grenjs
Re: Jump Start
Posted: 12 Dec 2008, 23:08
by Red Westie
"pooh" jump leads.
Just cannot supply the 175-240amps required by the starter.
And someone not really knowing how to use jump leads correctly? ie; connect........leave connected for a couple of minutes whilst raising the donor cars engine speed (1500/2000rpm) then start.
Even "pooh" leads will allow a good cross charge so that when it comes to starting the broken vehicle, it is not relying completely on the leads/connections and donor battery.
Martin
Re: Jump Start
Posted: 14 Dec 2008, 11:25
by jpee
Not pooh leads and do know how to use correctly.
Re: Jump Start
Posted: 14 Dec 2008, 16:43
by funbus1
Its cool ,I use a Bose starter battery as my leasure battery. Makes sense

Re: Jump Start
Posted: 14 Dec 2008, 20:38
by Mr Bean
jpee wrote:Not pooh leads and do know how to use correctly.
Escuse me if I am teaching granny but:
You need to know what current is flowing and where. You probably won't have DC meter say 0 - 400A but volt drop values can tell a lot.
First thing to know is does the battery volts hold up when you turn the key to start on a known good vehicle to get a feel for it.
Connect volt meter across starter battery terminals while you turn the key to start. Voltage can drop below 10V and still start motor. If no significant volt drop occurs then suspect starter or or circuit. The same test can with difficulty be done on the starter motor to see if the volt drop occurs somewhere along the line.
When jump leads are in place check both batteries under load in the same way. This will tell you something about where the current is going. If the jump lead connection is inadequate the missing volts will probaly be found by measuring voltage from Positive post of one battery to positive post of second battery and voltage from negative post of one battery to negative post of second battery. Look out for sparks or smoke which may be evident on poor connections. after some attempts to start go round feeling terminals and suspect points such as sharp bends on wires for hor spots. Do this gingerly in case of burns to your fingers. I know it sounds obvious but with the right diagnostic approach and some simple equipment it is posible to highlight the exact problem if only you know how. Give that a try and get back on with the results so we can help track your problem down. Unless of course you think that gremlins or fairies are at work in your electirics.
Good luck with it
Wolfie