Just been looking at relatives restored mk3 XR2i (90) and the new battery he got from local motor engineers was sparking when connected and all the lights came on so he left it
I checked out all the circuits and the only load was 0.5 meg ohm to ground on the alternator,(not enough to cause a spark!). But load shot up while alternator was connected. Suspecting fault on the diodes (battery had been discharging overnight and was recharged off the vehicle by supplying garage) disconnected alternator
Battery could now be connected with no load being drawn, however indicators wouldn't flash and stayed on

Going back to basics, checked battery and realised poarity was reversed, i.e it had been charged backwards by the garage and now has 12 volts plus on the negative terminal!
Stuck my spare battery on and the alternator was connected with no sparking
Wont now fire on turnover although lights and indicators and gauges all work and fuel pumps running and smells of fuel on the exhaust so think is injecting, so not sure if its took out the coil packs or after fit imobiliser, looking on here, ECU fail should revert back to 1O deg timing so should do something evn with that fried
Think it happened the first time he connected it as all the lights came on?
Be interesting to see how the blame is sorted
Anyone else had this happen
First for me as ex HGV and plant engineer