svengali sven

Have a 95 NG900 in good condition, but it has developed an odd set of problems and I was wondering if it they are connected. Firstly a couple of weeks ago it stopped while climbing a steep range. It coughed like it was low on fuel - it had a quarter tank and has a new fuel pump, had no power and idled like it was running on 3 cylinders. There's no water in the oil or vice versa. It wasn't running hot at the time. The engine warning light came on; but that's been coming on and off for the last month or so and my mechanic says it needs a new thermostat. Also over the past few months it has also developed some odd electrical ghosts. The interior lights come on and off even the though the doors and hatch are firmly closed - even when the car is sitting the interior lights come on for no apparent reason. The dash board and centre console lights also go on and off randomly. I started the car the other day and took it for a short drive and it is running rough, but seems to have its power back, but I'm not sure I trust it for the 9km drive to town. Has anyone got an idea? Is the engine problem really an electric problem and could they be connected to the lights coming on and off? The car has 320 000km, but uses no oil or water and always has had good power. any suggestions will be worthy. many thanx :-)