I have a 1998 Rover Mini Cooper Sport (1275cc). Battery died over the last couple weeks not running it, tried to jump start it today. It was dark, and my neighbour's battery does not have a colour indication of which is + and -, and the jump leads were the wrong way around. Horn blasted and some smoke came out of the bottom.
I took the leads off, tried jump starting the right way round, it started and sounded fine but immediately died when the jump leads were disconnected. I checked the fuses by the driver's seat and they're all fine. I'm not sure how to check the fusible relays in the engine compartment.
How much damage could have been done? What's the most likely fault?
Thanks all. And yes, I do feel like an idiot.