johnnycortina

I see 'uprated' radiator fan switches for sale - what is the uprated bit, compared to the standard switch? What does it do better?

Thanks.

Rsmat

iTrader: (2)

It comes in earlier and for less time...relieveing the fuse box from melting.

langer

iTrader: (1)

I've just fitted one into my new radiator from msd and it's much better than the standard one

Mike1

As said, the ones I've seen come on at a lower trigger temp and switch off after a shorter length of time as they don't need to bring the water temp down as much. Basically the fans will do shorter duration cycles but more frequently than the standard one. Worth getting an uprated fan ( and fuel pump ) loom as well

martysmartie

iTrader: (1)

It does in fact activate LATER than the standard one.

I always phrase it "Uprated" as it's merely closes at a HIGHER temperature than the original, other Ford cars had the exact same switch fitted, but it's a nice word to market it I guess.

The problem with the original COSWORTH switch is that it activates the fans too early and they stay on for far to long due to the huge span of the switch which is what leads to melting fuses etc, design was never a strong point, it was just plucked from the parts bin, despite Ford having the higher temp ones as well.

The fans should also be rewired, if you have not already done so.

Martin

johnnycortina

Thanks all - what should be done with fan wiring - replace with heavier wiring?? and where do you stop when replacing wiring i.e. how far back do you go into loom.

martysmartie

iTrader: (1)

Easiest thing is to bypass the original fan loom and rewire direct from the battery, protected via a fuse of course with an aftermarket loom or DIY, if you are that way inclined.

Looms are available from NYRS spares, MSD etc, plus, if you do a search on here, there is a lot of information on the subject including diagrams etc.

The fuel pump wiring also builds resistance over time and can lead to less power getting to the fuel pump, this again can cause a catastrophe as the pump cannot draw the power it needs when under load, so you can end up with a engine meltdown, again, ideally this needs rewiring using the same procedure as above.

These are two major weak points!

Martin

johnnycortina

Ok thanks - understand

robertthorpe

The 'uprated' ones are mainley for alloy rads because of the heat sink that occurs in ally rads making standard rad switches come on early and stay on too long because the alloy rad disperses the heat more so the switch gets hotter so it thinks the water temp is hotter than it acctually is. I just fitted one in my ally rad in my 3dr cossie build, works a treat!!! I gave my loom a good check over for now but will be getting rewire kit from msd in the future as its safe bet with cossie looms!!! Lol
Rob

martysmartie

iTrader: (1)

The radiator is irrelevent, it just so happens if you have an alloy rad you need one period, for the reason you stated, but in any case even without alloy they stay on for far to long, if not indefiently anyway!

The standard switch has such a bad span which is so far unsuited for the application it's untrue, as with the rest of the car, design was not a strong point!

Martin