ECU Fault?

Hi 850 20V non turbo - N Regd I have been having a strange electrical problem with my car and I read a very useful thread the other night which advised that if the electrics are playing up you can disconnect battery for 24 hours and the ECU will reset. I did this and wow I thought it had worked - for a couple of days. I have a situation where suddenly my Temp Gauge and Fuel Gauge go off and the SRS/ABS light will come on and the engine splutters. Well today this happened again and I turned off the engine. When i tried to restart there were no dash lights and a completely flat battery. I left it for a couple of hours and tried again and it started fine but now if I switch on and apply a load ( such as headlights or heater fan) the SRS/ABS lights glow dimly and go out if I rev the engine. Any ideas Thanks Steve

I would suspect the alternator has low output. Use a voltmeter to measure the battery voltage with the engine running, and with loads switched on and off. It should read around 14 volts. A meter can be bought cheaply at the DIY stores.

possibly a bad earth also?