The electric motor in my workshop is on the compressor, and that has an enormous capacitor on it.  Size of a can of beans.  Do others have them, drills and so on? In ignorance, I looked up how it might be wired to the motor, and found that there would be a centrifugal switch - to disconnect it once the motor is up to speed?    But if a cooling fan can draw 50A (!!) why don't they build a capacitor into the fan? Surely the motor speed could be detected electronically, without a mechanical switch?  Or am I just showing my ignorance? John

Switch illumination would be my guess too.  I think my fan setup has the manual override switch change between off, manual on, and the third position sends a live to the thermostatic controller.  Other than this difference it's the same as Hamish's setup, (20A fuse as I've only one fan).

Agreed. Also (relatively) easy to sort now while the tunnel cover is off….. Otherwise there’s a risk that each bump in the road will lower the ‘box a little until the flange is rubbing on the chassis again.

Ahh, the manual switch is a (SPNO) Single pole Normally open- third contact must be earth return for illumination, I guess.

Indeed!    If I may: This is the rear mount plate for my T9 gearbox.  https://sideways-technologies.co.uk/forums/index.php?/topic/9855-fitting-the-ford-t9-gearbox/ The 'box rests on the rear edge, via the two smaller holes;  the big one is for access to the bolt into the 'box  housing.   It's in  3mm steel, as OE, I arrived at it via CAD (CARD assisted design) which I tested by twisting it in my hands, a prototype in thin metal that I bolted in and stressed, and then when I too had clearance issues, had to bolt it under the chassis rail edge.     The original is pressed steel with flanges for stiffness, but I had to weld them on (fully welded topside). Hope that helps. John  

I think the sensor is duff. To top that my Zeitronix wideband in my spitfire has just packed up. I will try a new sensor, see if that fixes it. I don't seem to have much luck with widebands... I just wish they were fit and forget like you would expect, not sure if it is the controllers killing them.

I guess this goes with the “special” instructions about the “kenlow” switch   mine is a 2 contact 25amp switch.    my pre relay set up appeared to work on short term tests with a 30amp fuse. And with the relay only with a 30amp fuse and I left it running for a good 5 mins.   but with the relay the thermostat and switch have an ordinary 12 volts and not affected by the fans load requirements ?! this set up doesn’t go via ignition so the fan with run when parked up and hot.  This is the same as my TR. Not sure as to the merits on this as there will be now coolant circulating  but the bonnet is well louvred so residual heat will be blown out. 

Why is there A ground on the manual switch?

Found the previous post. Your custom mounting plate could maybe have done with some stiffening, in hindsight! A return edge perhaps. Easy to say now... 

A quick run up to the Tomintoul toad to catch the sunset and panorama of the Cairngorm with Ben Macdui and the cleft of Loch A'an