Can someone explain How the electric fan operates. Does it hit a certain temperate first? Is it suppose to stay on when the car is off? I ask because I have never noticed it on at all. I ran a hot wire to the coil so that it would be on when the motor was on, but I didn't notice any difference at all. Maybe it was working right and I just didn't notice, but a simple explanation would help my brain wrap around it. maybe I just need a new relay or something.

 

The electric fan is controlled by a temperature switch and a relay. In normal operation it rarely switches on as the engine temperature is "controlled" by the thermostat allowing or inhibiting the water flow to the rad. In traffic when there is no airflow through the rad is the only time when, if the engine temperature gets too high, the fan may switch on.
Provided your engine temp does not go too high and the fan, relay and switch are ok then no problems.

 

My fans very rarely turn on from engine heat(only on 40c + days stuck in traffic), but they do come on when the air con compressor is running. On my S1 the fan turns off with the key, but on my Jeep if they are running when I turn off the key they will keep running until temperature switch senses the right temp to turn off.

 

The fan should come on at 95ºC and, yes, the circuit is designed so that it might stay running after the key is turned off.


Here's some info

Aux Electric Cooling Fan Checklist, Series III


Cheers
DD

 

I'm guessing my relay/switch is bad. I've never heard it running, got under it when it was at 100 and it wasn't on.
Thank you for the info

 

Amaezing:


when you jumped to the fan from coil +, did you skip the relay and temp sensor?


If so, and the fan ran, it's motor is probably OK.


So, then Check your circuitry, ie the S57 Jaguar schematic. Examine the logic.
Example, and possibly the right one. the sensor forms ground at a preset temperature. That ground is the relay trigger. Power s from a brown, hot at all times. so, if the car is shut off and the temp remains above the preset, the fan will run til the temperature drops. Really neat tech.


But. let Doug's check list guide you. the acknowledged master of these cars.


Carl

 

Carl, yes I did bypass relay and sensor. I am going to go through the checklist here this weekend, but I think I should probably check out my injectors now first. They have pissed me off for the last time. I had an issue with one of my gas tanks the other day after I reset the throttle valve and not it's worse than before. I can't be without my car for the weeks that it would take to send them out and get rebuilt so I'm gonna see if I can't do it myself. Anyone on this forum done them before?

 

There's a shop right in Denver (you live in Denver, right?) that I used; took them in on a Monday, picked them up on a Friday. $25 per injector, and that was the cure for my ailing XJ6.

Fuel Injector Specialists - Home - Wheat Ridge, CO

PHONE #: 303 456 0789

I was very happy with them.

-mB

 

Thanks Mike. We still need to get together sometime. I live in Lakewood now, your over by Erie right?

 

the auxiliary electric fan is controlled by a Thermal Switch mounted to the bottom right side of the radiator, which signals the Red Relay mounted on the top left side of the radiator support, to kick the fan ON.

you can remove the Fan by first removing the lower grille, (under bumper), then test it with two wires connecting each wire to each battery pole, (careful, the fan will literally fly out of your hands, keep your fingers away from the blades!!).

if the fan runs, the next test is to replace the Red Relay, if that does not make it run, the problem is the Thermal Switch at the radiator.

 

Are you saying the fan needs to be removed from the car for testing? That's a lot of extra work. Just unplug the connector and use jumper wires!

Cheers
DD

 

correct.
Aux Electric Cooling Fan Checklist, Series III
this is a great article as well.

 

of course you can test it in place if you have 12 feet of jumper wires just laying around!!

 

Jose:

1. I do!

2. Extra battery. I now have one! Another story for another day.

3. It ain't 12' from the battery posts or either firewall post.

4. Closer sources of 12v. Head lamp connector or horn relay. Fog lights for those that have enabled the switch.

5. Jump box.

6. Two 6v lantern batteries in series.

7. Another car's battery, parked nose to nose with Jaguar.

8. I have a little box that drops 110v to 12v with leads. Actually a DIY dumb battery charger...

And, more, I am sure.

Carl.

 

in the early 1990's someone came up with a mod to make the fan run everytime the a/c compressor is engaged, even when using the Heater. The same way the 12 cylinder cars are wired at the factory.

I still have the mod instructions and the wiring done in my car, but I disconnected it because I was in Tennessee and you don't need the auxiliary fan running in winter when the opposite is true.

 

Carl,
it ain't 12 feet from the battery to the aux. fan, but it is 6 feet, and you need two lengths of 6 feet each to reach the fan from the battery, so that makes 12 feet.

 

Why the second one for ground ? A decent ground can be found most anywhere.


I am just being cantankerous. But, making up two six foot leads seems a lot easier than removing the grill!!!


Carl

 

I actually just pulled the plug out from the harness, turned it, put it back in on only the ground terminal and then ran the hot jumper to the exposed hot side. worked like a charm.

 

so if the fan is good, but it does not come on by itself, you have one of two potential problems: the Red Relay or the Thermal Switch. I would try first replacing the Red Relay with a known good one.

 

Almost next on the list. First thing now is getting the A/C working. Pump is bad. Draws all the amps so the alternator won't keep up, and it has a leak, and it's making the noise of "I'm done". I'll come back to this fan prob later.