Your comment on the alternator half reminds me of an issue I had a few years ago (but only vaguely remember), hopefully someone here will be able to explain this better than I as it's a right pain when it happens: After jump starting a car I found a sensor had died in one of the cars - I think the one I was starting but may be wrong. I found out this was quite common, the inductance of the jump leads allows a voltage spike to be generated on starting which can take out random lumps of electronics. Does this ring any bells with anyone?


The cure is, where possible, to disconnect the jump leads after charging the battery in the jumpee, although I seem to remember thinking that if that battery was in a fit state to start that car then it would be of low enough internal impedance to stop the problem anyway. 


I do remember that it would have been cheaper to buy a new battery than what it cost me to replace that sensor!



On another note, this was all much more fun in the days when some cars were negative earth and some were positive earth. I remember sitting indoors having a cup of tea while waiting for my positive earth Ford Anglia to charge from my dad's negative earth Renault 4 (later mine). On a hill. The handbrake slipped on one of them, it rolled down the hill, the bumpers touched, and there was an awful lot of smoke...fortunately they were very thin (probably home made) jump leads otherwise we could have had two cars with exploded batteries! Ah, we had to make our own entertainment in them days...


Cheers,


Andy

Your comment on the alternator half reminds me of an issue I had a few years ago (but only vaguely remember), hopefully someone here will be able to explain this better than I as it's a right pain when it happens: After jump starting a car I found a sensor had died in one of the cars - I think the one I was starting but may be wrong. I found out this was quite common, the inductance of the jump leads allows a voltage spike to be generated on starting which can take out random lumps of electronics. Does this ring any bells with anyone?


The cure is, where possible, to disconnect the jump leads after charging the battery in the jumpee, although I seem to remember thinking that if that battery was in a fit state to start that car then it would be of low enough internal impedance to stop the problem anyway. 


I do remember that it would have been cheaper to buy a new battery than what it cost me to replace that sensor!



On another note, this was all much more fun in the days when some cars were negative earth and some were positive earth. I remember sitting indoors having a cup of tea while waiting for my positive earth Ford Anglia to charge from my dad's negative earth Renault 4 (later mine). On a hill. The handbrake slipped on one of them, it rolled down the hill, the bumpers touched, and there was an awful lot of smoke...fortunately they were very thin (probably home made) jump leads otherwise we could have had two cars with exploded batteries! Ah, we had to make our own entertainment in them days...


Cheers,


Andy