Hi the the only car I have to jump start my own has no negative terminal so will it still work if the black lead is just connected on a metal part of each car?

  • 1
    How is it that there is no negative terminal on the battery? There is no such thing as a single-pole battery.
    – jwh20
    Commented Nov 18, 2019 at 18:29
  • Maybe there is I just can't see or find any way to access it.
    – Blazin
    Commented Nov 18, 2019 at 19:42
  • 2
    @jwh20 There are plenty of designs where the battery is not easily accessible. Some times its in the fender, under back seat, in the truck, etc... My Sprinter has the battery bolted under the drivers floor board. Generally in these cases there is a easily accessible post for the positive side of the batter but no clear point for a ground (since you can ground just about anywhere) but if you do not know this off hand then you would wonder where the ground terminal is.
    – narkeleptk
    Commented Nov 19, 2019 at 0:26
  • 1
    @narkeleptk's case is similar to my Transit - but on the Transit as well as a positive terminal under the bonnet there's a great big ring on the engine itself to connect the negative (I wouldn't be surprised if it's also a lifting eye)
    – Chris H
    Commented Nov 20, 2019 at 15:47

1 Answer 1


Yes. A good grounded metal part will connect to the negative of your hidden battery and is pretty much the same thing.

  • 1
    Best place to jump the negative would be a suitable place on the engine.
    – HandyHowie
    Commented Nov 18, 2019 at 15:21
  • Best place will be a good earth point on the chassis...
    – Solar Mike
    Commented Nov 18, 2019 at 17:49
  • 3
    @SolarMike Seriously? Read step 7 here - rac.co.uk/drive/advice/car-maintenance/how-to-jump-start-a-car By connecting the negative to the chassis you are adding the extra resistance of the engine earth strap to the circuit. The best place to connect the negative jump lead on the dead car is on the engine. See RAC photo too.
    – HandyHowie
    Commented Nov 18, 2019 at 19:17
  • @HandyHowie AA & RAC mechanics are not vehicle electricians and get 1 year's training compared to mechanics and electricians that do a 4 year apprenticeship. And, yes I talked with some - usually while sorting the things they could not... BTW the earth cables can be battery to body to engine or battery to body with battery to engine ie in parallel or battery to engine to body. The choice is usually which is the shortest length to keep costs down. Often there is no engine earth strap - it is actually fitted across one of the gearbox mounting rubbers as that is a shorter option.
    – Solar Mike
    Commented Nov 18, 2019 at 19:27
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    @SolarMike I doubt very much that an RAC mechanic took time out from driving his van to write that article. It also doesn’t matter how the engine is connected to the chassis, it is still called an engine earth strap and will add extra resistance to the circuit.
    – HandyHowie
    Commented Nov 18, 2019 at 19:48

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