Hi all ,    I'm new to the site so please forgive any breach in etiquette! 

I am a new owner of a 205 STDT 1.8 XUD7T. I am having trouble with the Fuel Gauge and the Rev Gauge .   The fuel gauge flickers wildly from full to half to empty quite randomly and sometimes seemingly is affected by acceleration.   I removed the fuel sender to check the plug and wires and all seemed good. I did find the sender covered in a very sticky greasy residue , most of which I managed to clean off and I could hear the float moving freely inside.
When I bought the car , the chap suggested that it was likely the “voltage stabiliser” on the clocks that may need to be replaced. I am not familiar with this , where to find it and where to source a new one (the right one). 
  the Rev Gauge does not work at all and as yet I have not had the opportunity to delve into that quite yet. 
  I did also have an issue with the blower fan not working at all but with a bit of a clean up of the resistor it came back to life. 
  apart from that she is in fairly good condition . 
  any advice on the fuel gauge and Rev counter would be very much appreciated . 
  Thanks in advance  Adam