Me again.
Well, it was a seized fan that caused the problem.
Stripped it to it's component parts and found that the bottom fan bearing was swimming in a rusty sludge.
Also one of the brush springs was jammed in (they are steel, one rusted solid)
So, stripped the motor down, cleaned all the rust and cr*p from the bottom bearing housing and drilled a small hole to allow any future water to escape.
Freed the sintered metal bearing from the shaft, soaked it in WD40 then engine oil.
Re-lubed it all and re-assembled it (having use the magic WD40 to free the rusted spring).
Checked the resistor pack, sure enough, the connection taking the live feed to the resistors has melted it's connection.
Re-soldered it, put it all back together and now have a fully functioning fan system again.
Fitted new glow plugs, as staring became a problem (two burned out but replaced all 4).
Also had an intermittent fault with the window switch not working when the door was open.
Stripped the loom from the body to the door and found 1 broken wire, 4 wires at the point of breaking.
The plastic covering on the wires has gone brittle, so I had to bridge the faulty ones with wire links soldered in.
I'll remake the door loom when the weather gets warmer.
Brownie points to me today

, back to painting the doors in the house tomorrow

I have earned my bottle of wine on Friday evening
