Radiator fan thermostat control

[dereksharpuk]

This has possible been mentioned before. Like some post USA Series 2 E Types, my twin radiator electric fans run continuously if the ignition is on. If it had air conditioning at some stage, it is now removed. What suggestions are there to fit thermostats? All it seems to have is a relay, no thermostats.What type, where can I get them, where should they be fitted? etc

[Bfastr]

If your car had A/C it would have had two relays on a small folded bracket on the front frame right about between the fans. is there one or two? the thermostat is called an "otter switch" and should be present on the top right side of the radiator as viewed from in the car, it will be on the front side of the radiator and have two spade lugs on it. those wires go to the relays. you need to study the schematic (if you havent already) to understand the basics of operation. having said that, if they are on all the time you need to figure out why, several things cause them to run all the time, One is IF it was an A/C car and the cabin A/C control is turned on it causes the fans to run all the time. second is if the otter switch stays "closed" or shorted, not as likely as if someone jumpered the connectors or bypassed the switch to force the fans on all the time to prevent the possibility of over heating. and third, IF both relays are present, the second one turns on the fans when it presents +12v to the second relay, hard to picture unless you are looking at a schematic. so, if they hard wire the blue/white wire to +12v all the time, then the fans are on all the time.

First thing to do is try to figure out what has been altered in the circuit by someone before you.

the usual culprit is people connect the wires at the otter switch together to cause the fans to run continuously, start there. should be a black wire on one lug, and black and red on the other.


Bob

[dereksharpuk]

Hi Bob, thanks for that, Well, my car is ex USA, converted to RH drive. The radiator does not have any thermostatic tappings for the radiator fans and only one relay. Any thoughts anyone? Personally, I don't think it ever had a fan thermostat and understand several US cars did have continuously running fans. So any clues as to how I convert to thermostatic control?

[Bfastr]

well.. I recall seeing a thermostat add on for cars someplace that basically was attached to the outside of the lower radiator hose and was adjustable for temp. Something like that might be your best bet.
as I recall it was tie wrapped to the hose so there was no need to cut or modify anything.

[Mark Gordon]

well.. I recall seeing a thermostat add on for cars someplace that basically was attached to the outside of the lower radiator hose and was adjustable for temp. Something like that might be your best bet.
As I recall it was tie wrapped to the hose so there was no need to cut or modify anything.

That sounds like the unit that I got from XK's, Bob. It was, like most aftermarket parts today, made in China and IMO a piece of junk. It came with several wires (about 5-6) that were marked as to where they went, but there were no written instructions, so I had no idea how to adjust the temperature control. I called XK's customer support and got no help what-so-ever. I went ahead and installed it and it worked OK in mild temperatures, but it failed completely while on a 500 mile trip in 80 deg. F. ambient temperatures. I ended up getting a Cool Cat system and have had no problems since regardless of operating conditions. My advice would be to contact Mike Frank at Cool Cat and ask for his opinion; he really knows his stuff when it comes to cooling issues.

CoolCat Express Corp. Jaguar Performance Parts
www.coolcatcorp.com/

[mgcjag]

Hi...whats your name.....can you pleaes try to put it in as a signature with your car model.......you have two ways to solve your problem......wire it up as per a S2 wireing diagram, including radiator otter switch....or an aftermarket temperature control to switch the fans on and off........do you have a wireing diagram...there is one in the knowledge base section..... Steve

[Bfastr]

Hey Mark,

thats good to know, I was skeptical when I see stuff like that too. but since the original poster said he didnt have connections at the radiator I thought about that device. I guess maybe he has an aftermarket radiator with no provision for an otter switch. if the car was transformed into a RHD car who knows what was done/undone.

I am in agreement with you, his best option would be to get with Coolcat and install a new radiator with otter switch.

Bob

[dereksharpuk]

Now spotted an Otter switch on the front of my radiator. Will investigate the wiring diagram, but I gather these switches are not very reliable. Might get a new one from Fosseway performance.

By the way. Anyone know the pressure relief settings for the radiator cap and the expansion tank caps. My expansion tank cap has a setting of 10-22 PSI.

[Bfastr]

well now that you found the otter switch, there should be two wires going to it.
if you disconnect either one with the key/fans on . they should stop. if they dont someone altered the wiring elsewhere and you will have to compare it to the schematic.

as for radiator caps the pressure rating depends on if you have AC or not.
There should NOT be a pressure cap on the radiator of a series 2. it looks like one, but it isnt.
the pressure rated cap is on the expansion tank. 7lbs for non AC and 13lbs for AC.

[dereksharpuk]

Anyone purchased this? http://www.s-v-c.co.uk/product/jaguar-e ... r-fan-kit/