Where is the Electric Motor that works the 'Cool Down' Fan? XJS V12
 

When you come back from doing a run and with the Engine up to Temperature, depending on certain conditions.

After you Switch the Engine Off, the Electric Fan in the Fan Shroud cuts in for about 5 or 10 minutes, to Cool the Engine down.

But where is the 'Thermostat' housed that makes this happen.

Not quite sure what you mean? The set up on my 86 coupe is the mechanical clutch fan and then next to it is the smaller electric fan which has its electric motor as the "hub" of the fan and a thermostatic switch on the radiator. The convertables electric fan comes on with the engine the coupes come on at a certain temp OR with the A/C on. All of course IIRC.

Sorry JT, had to do an edit, what I meant to say was:

Whereabouts is the Thermostat, that operates the Fan in the 'Fan Shroud'

OB
It is in the hub of the fan on the UK passenger side of the rad. This fan design is very old and inefficient compared with what is available now as you can see from the diagram, which is why people change then for more modern designs, even if they do not change the large engine driven fan for a large electrically driven one.
http://www.jaguarclassicparts.com/il...ges/me4072.png
Electric Fan and Motor-5.3 Litre - Parts For XJS from (V)139052 to (V)179736 | Jaguar Classic Parts UK
Greg

On my 91 the control unit is on the relay board on the left wing.

OB
It is in the inlet spout to the water pump. Look carefully just above where the bottom hose joins the pump and you will see a brass bolt like thing screwed into the water pump inlet housing, with two wires going to terminals on it.
8 and 12 in the diagram:
http://www.jaguarclassicparts.com/il...ges/me3152.png
Water Inlet Spout/Bypass Pipe-5.3 Litre - Parts For XJS from (V)139052 to (V)179736 | Jaguar Classic Parts UK
Greg

Hi Greg

Thanks

No wonder I couldn't find it!

I've been looking in all the wrong places.Lol

I wanted to fit an Over-ride Switch, to run it in an emergency Situation but the more I think about it, it seems that all electric, could be the way to go.

Cheers Malc

But not on mine apparently?

Got it Greg!

Many Thanks

OB
It maybe wired OEM to always be on with the aircon. If not, easy to redo wiring si it is. Then you do not need a manual switch. A more modern fan if installed, can just use the OEM circuit, all you have to do is unplug the OEM wiring and join them to the new fan's wires.
Greg

Hi Greg

Thanks, so you mean if its wired to the Air Con, I just switch the Air Con On?

On the convertible, the A/C is always on, or at least the compressor is engaged so the fuel cooler is doing it's job. They reprogrammed the Climate ECU because they realized that someone could drive on a nice warm day with the top down, but not turn the A/C on.

I don't think the auxiliary fan is wired on the convertibles to come on when the A/C is turned on since it is always on, but instead depends on a temperature switch/thermostat. I replaced my switch with one that triggers at lower temperature.

EDIT: Just looked at the schematic, and the only thing that controls the electric fan is the thermostat. If you wanted a manual switch all you would have to do is wire the switch to the thermostat connections and eliminate the thermostat.

I wouldn't recommend it though. The advantage of the thermostat is that it keeps the fan running after shutdown and runs until the temperature drops below the minimum. When the engine is hot enough for the auxiliary fan to be working, you'll really want it to continue working after shutdown.

Exactly so. My car was so wired OEM, but Jaguar changed it from time to time, so are, some are not. On some cars the electric fan comes on only if the switch trips, regardless of whether the aircon is on or not
Cars wired OEM so the fan was on always when the aircon is on used the thermostat switch to trigger the electric fan if the aircon was NOT switched on.
On my car this never happens as the aircon/heater is always on, as the car is undriveable otherwise!.
Greg

Hi Mac

I just wanted Manual Override, to keep the Fan running longer, after it switches itself off, or just power it up, if I wanted extra Cooling.

Looks like a simple wiring job, now I know where the Thermostat is Thx. 'Greg'

Hi Greg

Thanks

I've been busy with other Stuff to day, so when I get the Car out, I will see which wiring version I have got.

OB, here is the 1990 schematic

Excellent Mac!

Thank you very much for Posting that.

After looking at Gregs post l checked my model year and the thermostats in the same place, maybe the control relays are too on yours. For a while l fed a live there and had the fan on with the ignition.

On my 94 convertible the aux. fan comes on only by the thermostat. Usually when the temp gauge gets just on the right edge of the N. The air con has nothing to do with it and my air con only runs when I turn it on. It is surprising how there are so many differences between the model years.

I plan on going to all electric fans. The cooling system overhaul is the main project for next winters down time.

...Jimmy

Hi Malc

I was also thinking of wiring a live feed but may not need to do that, if it comes on with the Air Con.

Weather too iffy to get the Car out at the moment.