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Battery Died, Still Can't Get Car To Crank Off Another Running Vehicle.


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So there was a lead hanging off the postive terminal and the tape came off in the hot weather when it was sitting in the shed and earthed the battery out for a good week completely cooking it.

Now I removed the battery and tried to start the car via jumper leads directly off another vehicle but it just goes whir.... whir.. whirrrrrrrrrrrrrrrrrrrr and won't properly crank. Does the starter require too much current to draw entirely via jumper leads? Or is it likely I have another short or have partially blown a fuse limiting current?

Cheers

I'd say it's the jumper cables you're using mate. Most cheap jumper cables that you buy from Supa Cheap etc actually just have very thick insulation around what is probably only 8 or 10 gauge wire, so they can't provide enough current to jump start a car unless the battery only just doesn't have enough power to start the car anyway.

For example, this is my cheap set of leads that I bought for $20 from SupaCrap:

IMG_0102.jpg

Compare that to this set of leads that I made myself from 00-gauge cable:

IMG_0105.jpg

My battery frequently goes flat as the car may sit for awhile without driving. With the set of leads from Supa Cheap, I could never get the thing started, I always had to take the battery to Battery World for a charge. With my set of leads, the battery has never been flat enough to not jump straight away and I've had it as low as 7v (dead, in all rights) thumbsup.gif

if you wanna use normal leads you need to have a battery there that can hold atleast a small charge then let it charge for 30 seconds or so before trying to start. also if your leads are struggling you can try putting the positive jumper onto the left post (looking from the front) of the starter motor and the negative onto a good earth on the motor (i use the front intake manifold nut where the earth cable bolts on) to help things out a little.

Let the other car charge your battery, I had this happen to me you can feel the heat through the insulation due to the poor thickness. A good way to make strong leads and cheaply is using welding cables, they can pump up to 300a and are much cheaper than car stereo cabling which can do about 200a at 4 gauge thickness

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