One for the boffins... Fan switch / resistor thing.

[Roy Kemp]

Ok chaps. Here's a puzzler.

While stripping out the original Ford steering column, I noticed a plug onto a spade mounted on the top of the column. Thought no more of it until of course, I was bolting everything back together and, of course, the Corsa column doesn't have one.

I rake among the discarded bits and find this. This was screwed (using a bloody self tapper) onto the original steering column. The old man (ex Ford mechanic) has identified it as a heater resistor. This would have been mounted on the blower motor of the original car, and a number of these resistors would have been used to give a volt drop for different fan blower speeds.

 

A further point worth noting, into it is plugged a brown/white wire which a previous owner has marked "Fan Switch".

Now, here's the point I find puzzling. My car does not, nor does it appear to have any other wiring for, any sort of heater / blower / demister. The only hint to the existence of one at any point in time is a pair of vents at each end of the dash, neither of which is connected to anything.

So, if it's not for a heater blower motor, WTF could it possibly be used for? The radiator cooling fans work perfectly well without it, so it's not that.

Anyone? One-hundred bloke points for a worthwhile answer!

[Steve Kerswell]

It's a "thing" used for removing stones and clients from horse's hooves, trust me I'm a welder :-))

[Roy Kemp]

100 bloke points in the post to you Steve!

[Steve Kerswell]

many thanks Roy :-) how flints became clients I have not worked out ?

[Roy Kemp]

Gotta love that 15 min time limit for editing!

[James Doulton]

If it was the only thing connected to the switch then it was redundant. The switch should be connected to the fan motor and to earth as well as to the resistor. The fan would be permanently supplied from the ignition and be earthed for full power or earthed through the resistor for low speed. That is what the escort wiring diagram shows.

The fan and heater were probably removed because the heater matrix was leaking. Just a guess.

[Roy Kemp]

Been thinking about it overnight James and my car has had the transmission tunnel cut out and refabricated to accommodate the larger MT75 gearbox. It's just possible that there was a heater blower in there, but it was subsequently discovered that it didn't physically fit once the new tunnel was installed.

[Adrian Southgate]

The standard ford escort heater was two speed. Full on was a direct connection, half speed went through a resistor. The amount of current going to the motor would have meant a heat sink of some kind was required (the steering column) Chances are your car had a heater box when it was first built but it was later removed complete with all the pipes. It should have been in the space under that dome on the bulkhead / scuttle - if so there would have been two holes (or one oval hole) on the drivers side near the clutch cable aperture.

Oh... and the mk1 and mk2 escort both used a resistive positive circuit. Ign feed to resistor 'IN' , two wires out going to the fan switch and then one switched wire going to the + side of the fan motor.

[Roy Kemp]

I did wonder what the big Darth Vader's helmet arrangement was for. Not actually looked up inside it, who knows, it might actually be there after all! It would explain why there's not a random disconnected plug for the heater anywhere - it could still be plugged in! Ha ha!