5 replies to this topic

[saab]

Hello Guys

I'm feeling a bit foolish and I was hoping you can help me. I normally keep my car activities to Swedish makes - I have a T5 Volvo at the moment, but my girlfriend tools about in a '99(T) Mini Cooper and recently the battery went flat - not for the first time - the imobiliser tends to run it flat at my g/f barely uses the car. Tried charging it up but it wouldn't hold a charge so I decided that the battery was dead and needed replacing.

Bought a new one from Halfords - fairly certain it's the right one and popped it in the car just as I had done man times with the old battery. This time however I noticed the one of the two red cables connected to the positive terminal was flapping about and not connected to anything. It may well never have been connected, but I just happened to notice it this time and connected it up to a bolt which looked like the cable had been connected to. Then I connected the terminals up - a bit of sparking which I put down to some protective oil on the terminals became lots of sparking and lots of smoke. In a panic thinking the car was about to burst into flames I rolled the car out of the garage and managed to disconnect the battery (burning my hand in the process) - the cable from the positive terminal is totally fried and now I don't know what to do - I'm concerned that when i try and attend to the problem again the same thing will happen and not being able to stop the smoke next time and the car going up in flames.

I'm rather clueless when it comes to car electrics (as you may have realised) and I'm sure someone will look at this and shake their head in despair. Pics are below. The main questions are - what should (if anything) the long red cable from the +ve terminal be connected to? (the pics show the bolt I connected it to - nearest the end of the cable) - and secondly is it likely that any damage to anything else electrical has been done?

The AA are on the way but any advice is much appreciated.

Thanks for your help.

Jamie

[NateDogg2909]

Poor lad,

Normally the plastic sheath on cables melt when the core gets hot. Hot cables normally mean a short somewhere in the line.

It was probably that loose cable shorted with the body work drawing all the 60-odd amps the mini battery can provide. You did the right thing by whipping the terminal off because a shorted car battery at source normally turns into a acid bomb, which is nice.

The cable and terminal now need replacing but you need to check whether the cable is knackered beyond the point you can see in your boot. You can prob get the cable and terminals from your local motor-discount shop.

PS. check your fuses you mite have shot all those as well, sorry.

Nate

[saab]

Thanks mate,

Boy do I feel stupid - the AA bloke said more or less the same thing. He had worked as a Leyland mechanic for years so knew his stuff, but he had no idea what the stray cable was, but suspected it might have been used to power an amp or something similar at some stage. Basically by connecting it up to the bolt I had effectively joined the two terminals of the batt - with predictable consequences. He checked over the electrical system and everything seems fine - the earth connection needs replacing but it's still ok until I get a chance to change it.

Cheers

Jamie

[Sprocket]

There is not normally two posative wires in the boot!! It may have been for a mahoosive sterio amp by the previous owner

I suspect you have grounded the battery with the 'other wire'

60 amps? LOL how about 200+ more like

Personaly, i think the battery may well bedamaged internaly, the lead post looks a little melted as well, but its worth trying it. Just remove that burnt wire, do away with it. There should be nothing wrong with the main battery cable or connector.

You are a very very lucky man.

[saab]

I count myself very lucky indeed. The big amp suggestion is probably correct as there is a lot of high quality speaker cable in the boot running into the car but not connected up to anything. There is also a Thatcham cat 1 system installed which may mean there was some pricy stuff installed at some stage. Still the burnt cable is now disposed of and there doesn't seem to be any problems with the electrics so far, so all in all a lucky escape I reckon.

[Sprocket]

Really good to hear