Thats the fan fuse holder alright mate, unfortunately it is a standard problem so many of us have made a byepass system or bought one in to overide it all.

Tabs has done an explanation on here recently on how to rewire it and coswurv on here was selling one ready-made that he does - send him a pm maybe?

As for heater, could be the matrix in the dash - but before pulling it out try to flush it from the engine bay.



If its blocked this is how far you have to go to get it out!



Mine had a wierd problem though - the 'new' Ford pump had not been drilled correctly ;-(