I’m looking for technical help or recommendations on: __
Hi,
I am rather puzzled.
Today I put the battery back on my 2010 NC. It’s been on charge for the last 3/4 days. The car was running when I took it off.
Now as soon as I connect the battery, all the indicators come on - solid light not blinking. Also the wipers are sweeping. they won’t turn off, but they will go faster. The lights will turn on too. However, nothing else works. Turning the key does nothing - blank display, won’t start: doesn’t even crank. The radio won’t wake up either and it won’t/lock unlock either off the remote.
Sounds like many things: malfunctioning sticky relays; wiring damage passing current to places it shouldn’t; short circuit so ignition isn’t getting power, although that could be a blown fuse or relay again.
Check your fuses and relays, swap the relays around where compatible to save having to test them on a bench.
I once read of a similar problem and it turned out to be rodents nesting and chewing about the vehicle.
It was fine last Thursday. No visible signs of any damage.
CL won’t work either. It appears like the electronics have disabled the car. Rodents break things they don’t rearrange things. The indicators lights all come on as do the wipers irrespective of switch positions. None of that makes sense.
The battery came off the charger showing 14v and fully charged. What I didn’t see was that it’s reverse charged. I didn’t think an electronic battery charger would do that. The battery was at 0v when it went on charge.
That battery is getting flattened to recharge it the right way round.
In the meantime I have hooked up another battery with jump leads to test it.
All the lights, wipers and windows now work and the panel lights up. The radio doesn’t turn on and the security light is off. If can hear the fuel pump prime, but nothing happens when I turn the key. I haven’t found any blown fuses. I can’t scan OBD as my scanner is in another car 60 miles away.
“CL won’t work either. It appears like the electronics have disabled the car. Rodents break things they don’t rearrange things. The indicators lights all come on as do the wipers irrespective of switch positions. None of that makes sense.”
Mice eat wiring looms, and not in a consistent manner- I keep traps( humane - but you have to check them), repellent and and electric repellent all round my 5, as the blighters come in the garage in autumn and I have seen evidence of the odd nibble. None since precautions.
A few years ago they chewed 2 Elan looms to destruction - fortunately not in cars!
“That battery is getting flattened to recharge it the right way round.”
Quite impressive that you managed to charge it “backwards”. After doing that to it, twice effectively, the chances of that battery surviving very long are extremely low I would have thought. I’d be buying a new battery.
As long as the battery is discharged gently before the recharge, you should end up with a battery that works for a little while at least. I was once given a tip to use a high amperage boost charger on a dying battery for 10 -20 mins to pulverise the lead sulphate that builds up and restore some life to a dying battery. According to my informal experiments, that does indeed seem to work. Either way, you will now have a battery with a shorter lifespan.
So, effectively, the battery has been connected with polarity reversed. I can tell you from experience that this blows the main fuse on a mark 1, and as your ignition doesn’t seem to be doing anything, you may want to have another good look at fuses and relays. If I were you and trying to start the car with a good battery didn’t result in anything, I would check all associated ignition components, then feed 12v direct to the starter motor. Reverse polarity can do some really whacky and wild things to a car. I do hope your ECU has not been affected, although I think the NC’s ECU has enough diodes and whatnot to protect the circuit board from reverse polarity. Not sure on that, though.
Also, you say security light is off. Do you mean it behaves normally and turns off when it should or that it is totally off?
Some of the circuits that are fed through the main fuse work, so it can’t be blown.
The clear topped ones look OK, but I will meter them anyway. The battery has been slowly discharging through a 55W hand lamp. It’s down to about 0.5V loaded, so has a way to go.
Yes, I mean the security light is off completely. The cluster does it’s usual sequence i.e. it does lamp test and flicks the dials. I think all the lights come on, except the security light, then things like child air bag light go out.
How you managed to charge the battery in reverse polarity is amazing. DC will only flow in one direction so I find that impossible. You haven’t said why you took the battery off in the first place? Putting a battery on charge for 3/4 days will do it more harm than good, just sulphates the plates. Look at it logically, if the car works with a doner battery and not the original one
Very simple. The battery was totally flat i.e. zero volts. I used a doner battery and jump leads to move the car a little way to get it out from under a tree. I thought the battery was disconnected, but had forgotten to do that some months before, that’s why it was flat.
And as for reverse charging, a wet lead acid battery has no polarity intrinsically. It can be charged either way round. As it was completely flat, the charger couldn’t tell. I was in a hurry in a poorly lit room and didn’t notice the clips were on the wrong terminals. The + and -are just moulded into the black case.
It took 3/4 days to trickle charge to full. If you charge at high current, it will show fully charged, but it’s not.
I have flattened the battery slowly over several days and it’s now pretty close to full charge the right way round.
The only problem left to fix is replace the battery clamps as they are very stretched. I suspect a previous owner used a battery with posts that were too big.
