Sensible wiring for fan?

[JONZO]

I now seem to have a fan that only comes on when it feels like it. I had wired in an over-ride switch which gave me comfort for a while but now that has stopped working too. I checked the switch connections and the fuses and all seem in order.
First question is:- can relays be temperamental in that one day they work/one day they dont?

In desperation i now intend to give the car to an autoelectrician to possibly re-wire everything involved with the fan/otter switch/relay etc in order to finally cure it once and for all (as it looks like a chimp did it before). I dont know what other S2's are like but the wiring to my fan & otter switch seems to pass through several small junction boxes/fuses/relays?? (not sure what they are) on the way from the fuse box.
Has anybody done this before? and/or can anyone provide a simple circuit set up for the bare minimum thats needed. ie a dedicated line just for the fan & its relay (incorporating the over-ride switch).
Or should i just trust the auto-eleccy to solve it all?...any ideas what sort of price i should get charged for something like that?
Thanks in advance,
Mark

[F908 Tim]

Hi Mark.
YHM.
Seem to recall a labelled diagram in the bible that might be useful.
Good luck.