Wow. Photos of a brand new POS heater valve. Never seen one, and can’t imagine why anyone would $pend the money on one. Nice 'n shiny, though!
Kirby,
I compete some of my Jaguars in JCNA concours. Some of them have scored in the very high 99.9X range in Champion Division competition and have finished as the North American Champions in their class. As a result I try to keep my concours Jaguars as authentic as possible. The OEM heater valve in one of my concours Jaguars failed in the open position and I replaced it with an OEM one to maintain the car’s authenticity and the it’s fully functional heat and air conditioning system. An incorrect aftermarket heater valve is a 2.0 deduction in JCNA concours. I know that cheaper plastic substitute heater valves are available, but I purchased that OEM one to avoid getting that deduction.
JCNA concours is not for everyone, but I have enjoyed it as an Entrant, Judge, and Chief Judge (for a few years) over the past 12 years with 4 of my six Jaguars.
The OEM heater valve is nice and shiny and adds a nice golden glow to the firewall area. I would miss it if I replaced it with one of those black plastic aftermarket heater valves. 
Paul
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thanks very much chaps for all the input here. I have got the flu (manflu) so won’t be going into the toy cupboard for a couple of days to carry out more tests. I have not gone awol and will be back with results. cheers Andrew
Ok so to follow up , I tested the servo function by connecting the red and purple leads on the female side of the plug feeding the amplifier to a 9v battery. This actioned the servo and it moved to its extent of travel. By reversing the leads it then moved all the way back. So it would seem that it may be a faulty amplifier. I am just trying to work out if it could be anything else before investing in a new amplifier. Happy to do so if there are no other problems. If anyone can add to my test schedule it would be much appreciated. It occurs to me that there are so many inputs in this system, it could be anything thats causing the servo not cycle in response to temperature control inputs.
Years ago I read that faulty amplifiers were usually dry joints & easily
repaired.
Jim Brighton UK XJSC 3.6L
So, did you then drive the car and see if you got hot air? Just because you can hear the servo move doesn’t mean the system is working.
Just a tip: There are owners who have gone the cheap route and replaced the amp with a rocker switch. Push one way for a few seconds to make it cooler, the other way a few seconds to make it warmer.
Jim,
If Andrew’s car has the Delanaire MK II climate control system and the OEM C45402 A/C amplifier as ahown in the attached picture, the electronics are encased in a hard solid epoxy “brick” that is nearly impossible to remove in order to access the components. There are lots of posts about this in the Jag-Lovers archives from those who have tried disassembly or reverse engineering and found the OEM A/C amplifier nearly impossible to repair. Just search for “A/C amplifier”. There are a few aftermarket versions that have come and gone in the marketplace. I had a few of them. The OEM A/C amplifier has a high failure rate, as I can attest to from my experience in my two Series III XJ6s. The one shown in the attached picture was a good one that I puchased on eBay when one failed in on my XJ6s. I purchased several of these used A/C Amplifiers on eBay that the Seller’s thought were good but proved to be bad when I tested them in one of my XJ6s with fully functional heat and air conditioning. Eventually I found a good A/C amplifier that returned that cars climate control system to proper operation. I think that I have had three or four or the OEM ones fail on me overbthat past 19 years.
Paul
Ugh. So, where are our electronics weenies? Surely somebody can put together a schematic for fabbing your own A/C amp.
Kirby,
Some have already done that.
There is a USA business called Jag-Aire that sells aftermarket and refurbished parts for the Delanaire MK II. The owner is a Jag-Lovers member and posts from time to time. His name is Gary Crosby. His website is: www.jag-aire.com
I purchased one of his manual control products a few years ago to help me sort out an A/C problem in one of my XJ6s and once I got the A/C running again in that car I purchased one of those aftermarket Australian “shotgun shell” A/C amplifiers to put the car back to fully automated climate control operation before selling it.
There are a few other aftermarket A/C amplifiers out there. I think that John’s Cars in Texas used to sell one.
I have no affiliation.with John’s Cars or Jag-Aire other than as a satisfied customer.
Paul
thanks Guys as always. I didnt get to drive the car or get it up to temperature, that is tomorrows planned exercise. I have been in contact with Jag-Aire and have found Gary to be really knowledgeable and helpful. Again I have no affiliation with him or his company.
Yes mine is a Delanaire Mk11 . Hopefully I can confirm for sure that system works fine if the amplifier is sidelined tomorrow.
Well many weeks after I had hoped to resolve the problem of my lack of heating , I have now managed it. I purchased a replacement amplifier from Jag Aire and this immediately solved the problem of the servo not moving across its range. I received superb help from Gary Crosby and back up to help resolve my problem. IN fact although I had flushed the heater matrix I had not flushed it in the correct direction . I removed the outlet from the heater matrix and connected a hose pipe attached to mains water. At the pipe up from the header tank I attached another hose and led this over the side of the car onto the ground, well actually into a receptical so I could see what was coming out of the cooling system. I ran this flush for about 20 minutes and a lot of rubbish came out, in spite of the fact that I had fitted a new radiator core. Hooking it all back together after this and filling with coolant and hey presto, I have a heater! So thank you all for the help. I had a number of different problems starting with loose micro switch on the mode control, followed by a intermittent amplifier and finally crud in the matrix. Another problem solved with help from Jag Lovers.
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