Does anyone have a part number for the Thermostatic Switch used on a 1995 XJS with a 4.0? After spending a lot of money at two repair facilities (one specializing in Jaguars) trying to get my AC to work properly I decided to try and fix it myself. After finding a leak in my condenser, I replaced it and the drier. I pulled a vacuum and installed the correct amount of R134. The AC works fine except the auxiliary fan does not come on for the condenser. I have figured out the Thermostatic Switch is bad. I have had no luck in finding a replacement. I have temporarily made a loop with fuse to bypass the switch, but the fan runs all the time. I have to open the bonnet to pull the fuse to shut the fan off. If the Thermostatic Switch is unattainable, is there an alternative out there?
Fred, you can rig up a switch, accessible from driver seat, to complete the circuit when you want the fan to run…take the place of the the thermostatic switch
And I believe Paul Novak did a mod wherein he uses the Caravan warning light as an indication of when the fan uis running.
Are you referencing the PRESSURE SWITCH DBC11279?
I needed one for a 4.0 XJS customer car. (could not find one)
I fashioned a setup with 2 different brass fittings and a female A/C binary pressure switch.
The setup works and it has been several months since I installed the parts, the A/C still works fine.
I researched the thread sizes and ordered everything from eBay.
No idea what country you are in, but sellers in the US had things to make this work properly for less than $50.00 US.
I think the part # is CCC7145, but I am not sure as I have not been able to see an image of the actual switch being advertised. I can give you a decent description: it is brass with a black epoxy center with two small wires coming out of it, both white (one wire has blue dots) the wires are about 8 inches long more or less and have a PM5 female connector. The switch screws into the left side of the radiator and takes a 30mm socket to remove. I think the switch is supposed to make contact inside when the radiator warms up to complete a grounded circuit which turns on the condenser/pusher fan.
I may have to put a toggle switch in the cabin if I can’t find a replacement switch. I am going to get tired of having to open the bonnet every time I want to turn the auxiliary fan on or off. I was really hoping to find the correct replacement part. Summer is fast approaching here in Texas and I will be needing AC soon. I usually drive with the top down, but when it’s 100 degrees you get to looking for some cool shade provided by the top up and the AC on.
I just powered the electric radiator cooling fan from the ac clutch wiring, that way the auxiliary fan was on whenever the ac was on, in addition to being thermostatically controlled too.
I used the ac clutch wiring to pull in a relay, and fed the relay 12V+, through an inline fuse holder, from the 12V+ in the engine compartment.
Of course, being in Florida at that time, the ac was on practically all the time the car was running. 
Sounds like a viable option instead of trying to find this “manufacturer discontinued” switch. Thanks for the info!
I was about to suggest the same thing!
Easy and elegant solution.
Thanks for your interest!
The RADIATOR temp switch has nothing to do with the A/C.
The 30mm thermostatic switch (and AUX fan) is triggered by engine coolant temperature.
The AUX cooling fan is INDEPENDANT of the climate control system. (A/C has no relationship to the AUX fan)
See electrical guide S72_96_4L figure 24 for clarification.
motorcarman is correct. Your AUX fan is not connected to your air conditioning and it is probably working correctly. On both my 95 6.0 and 96 4.0 the aux fan does not come on until after the temp gauge is above the “N”. I originally thought the switch was bad and replaced it. I figured it out later that the switch was fine. The replacement was a Intermotor 50200 (92c - 87c) available on Amazon for about $20. It has prongs instead of wires so you have to attach connectors to the prongs. I recently purchased 2 90c - 85c switches which will turn the fan on a little sooner.
I see what you are talking about in figure 24. I don’t know why someone doesn’t make a suitable replacement for the 30mm Thermostatic switch. My A/C sure works better with the AUX fan working properly. Thanks for your expertise.
DAC6794 is the original part.
We never sold very many and by the time I decided to stock up, they were gone. It’s on the list to investigate adapting an alternative.
FWIW, on my 1988, the auxillary electric fan is connected through a diode relay (blue) to my interior climate control. The climate control is also connected through a relay to my extra air valve on A bank.
So even though i have removed my AC compressor, simply turning on the interior climate control fan engages my aux air valve AND electric fan.
I had to disconnect top wire on diode relay, and remove idle control relay to stop this.
We understand that.
We have made the obvious change because of that.
We wired the AUXILLARY fan to OPERATE WHENEVER the ac is operating to accommodate the extra heat being dissipated to the air in front of the radiator, which is also trying to dissipated heat to the same air flow path.
Which Is what Jaguar started to do.
Like i said, my 88 does that by design.
I am almost certain that the VW Jetta thermostatic switch (part number 321959481G) will install in the radiator threaded hole and it has three terminals with 2 temperature switches.(102-91c HIGH) | (95-84c LOW)
You can choose what terminals/temperatures to use and they are a standard 1/4" spade.(easily connected/adapted)
You should keep the radiator switch in the system and not rely on the A/C circuit to totally control the fan.(parallel circuits)
I faintly remember having to install a VW temp switch in a Jaguar a long time ago.
Right Greg. According to Kirby Palm’s book of experience the design was changed in 89 to discontinue the simultaneous A/C and aux fan. Which is why many owners of 89 and later cars rig up a method of their own design.
My XJS is an 83 and was not wired (from the factory) with the ac also (“also”, i.e., a parallel circuit) turning the auxiliary fan on.
I had to wire that in myself.
That’s interesting Jerry. Are you the original owner? I have no experience with earlier cars. Only my 95, v12 (and I am not the original owner) and things I read in the forums.
The variance among XJS’s on this and other forums has been interesting, to say the least.