Jumped battery the wrong way round
Discussion
A friend at work had left his lights on last night and by the morning his battery was flat. He jumped the battery off his other car but accidently attached the leads the wrong way i.e positive to negative. He relised after about a minute when the car wouldn't start, so he swapped them the right way round but now the car won't start. I took a look this evening a tried my battery but no luck. When you turn the key there are no noises and only a couple of lights come on the dash, The lights still work. The car is a 2007 Toyota Auris 1.8.
Is jumping the wrong way likely to have fried some electrics? I checked the fuses and couldn't see any blown but not sure if it's burnt something inside. Does anyone have experience of this?
Is jumping the wrong way likely to have fried some electrics? I checked the fuses and couldn't see any blown but not sure if it's burnt something inside. Does anyone have experience of this?
Some newer Jap cars (and probably others) have fuses on the battery 'terminal'. It bolts onto the battery positive clamp and distributes power to two or more seperately fused cables. Easily missed if you haven't come across them before. Otherwise go round all the fuse boxes. Something will have gone pop.
I did it to my Leon, apart from it was straight on to the starter motor so didn't noticed the spark til the car died thought I'd fried the whole car, replaced the battery and it was fine. Two weeks later went to jump start friends tractor. Thought he was competent let him put the clamps on the battery touched them off my 'new battery', massive spark realised what was happening luckily wasn't on long enough to any damage!
As for the Toyota don't know what to say but we've all done it luckily I got away with it.
As for the Toyota don't know what to say but we've all done it luckily I got away with it.
RussH91 said:
...don't know what to say but we've all done it ...
Errrm...no, we haven't all done it. In 45 years of pratting about with vehicles, I can honestly say I've never done that. How can bright red be mixed up with dark black? Even a blind
on a galloping horse can see the difference surely?You need to go through all the fuses and "fuseable" links carefully, checking for failures. (some fuses maybe actually in the wiring loom, or mounted on the battery terminals of any obvious power distribution boxes underbonnet or underdash etc.
Electronic devices in the car are protected to a degree from a reverse battery connection, however, in the event of a sustained wrong connection damage may well have occurred, which will mean new ECUs etc........
(generally, the "lower power consumption" devices can withstand a reverse connection indefinitely, because they can be fully protected easily with small diodes that stop current flowing the wrong way. But, high power consumers, like the engine ecu, alternator and ABS module etc, are more difficult to protect completely (for reasons that are too long winded to go into here) and although they will survive short mis-connection, they will be damaged by long term (>5 to 10sec say) reverse voltage. These modules are protected using a crow bar diode, that will effectively short the supply when it is connected the wrong way around, the idea being to hopefully blow a main fuse before the module is damaged. That damage is thermal, as those shorting diodes and the wire/tracking connecting it cannot possibly survive the huge short circuit current indefinitely.)
Electronic devices in the car are protected to a degree from a reverse battery connection, however, in the event of a sustained wrong connection damage may well have occurred, which will mean new ECUs etc........
(generally, the "lower power consumption" devices can withstand a reverse connection indefinitely, because they can be fully protected easily with small diodes that stop current flowing the wrong way. But, high power consumers, like the engine ecu, alternator and ABS module etc, are more difficult to protect completely (for reasons that are too long winded to go into here) and although they will survive short mis-connection, they will be damaged by long term (>5 to 10sec say) reverse voltage. These modules are protected using a crow bar diode, that will effectively short the supply when it is connected the wrong way around, the idea being to hopefully blow a main fuse before the module is damaged. That damage is thermal, as those shorting diodes and the wire/tracking connecting it cannot possibly survive the huge short circuit current indefinitely.)
littleredrooster said:
Errrm...no, we haven't all done it.
In 45 years of pratting about with vehicles, I can honestly say I've never done that. How can bright red be mixed up with dark black? Even a blind on a galloping horse can see the difference surely?
Do apologise for sweeping generalisation sorry if caused you such offence. Was trying to make OP not feel as bad as it does happen from time to time.In 45 years of pratting about with vehicles, I can honestly say I've never done that. How can bright red be mixed up with dark black? Even a blind
on a galloping horse can see the difference surely?When I've done it was generally dark, cold miserable, morning rushing trying to get a piece of s
t scrapper tractor out of the way. So I could get on and feed, scrape cow sheds etc on little sleep with no bright red bit of plastic over positive or black over negative, only the little plus or negative symbol in bedded in the battery casing which I've never really taken to reading brail with numb fingers.But seeing 'a blind
on galloping horse' try to jump start a vehicle would definitely be an interesting spectacle. Gassing Station | General Gassing | Top of Page | What's New | My Stuff