strange problem with the electrics
 

Hi all

Have just bought a Passat 1.9l tdi 95mod. There is just this one problem. When I turn on the lights the rpm counter(?), clock and warning lights goes off. So today i forgot the lights and everything was fine except i noticed the motortemperature was rising and the warninglight starts blinking. I turned the lights back on and the temperature is going down.

What could cause this?

Thanks