If you have the temp selector set to heat and you still have air coming from the center vents, it's absolutely not working properly, heat is not supposed to come from the center vents. In heat position, the levers on the servo unit at all the way up and heat is delivered through the side
Vents and floor vents. These amplifiers and their relays, especially the relay that switches from heat to cold, are prone to failure. Try hitting the amp on the end opposite the relays with a hammer. Hold the amp with the large flat side in your hand, that would also be the bottom of the amp. Hit the amp with the hammer on the small end striking toward the relays. I have seen three amps start working properly when this is done. Also the small blue pot. That is accessible , move that control back am forth to ensure that it has contact. When then temp control is on the 75 degree position, it adjusts the air to allow to make the system accurate to having 75 degree cabin temp. Also be absolutely certain that the ground for the amplifier is good. And those inline diodes, if they fail, the servos will not respond properly. That's about clears it up!! As far as
My experience goes. Lol. Paul

 

If anyone needs a XJ6 air conditioner amplifier I have plenty of them available for the lowest price $200 guaranteed to work. If the amp is your problem . all solid state not the relay type that came originally, direct plug-in

 

Hello, just reading a old thread. I have a 84 xjs that the a/c works except for the temp control and climate auto. So just blows cold and starts to ice up I guess. the compressor runs without cycling. Maybe the amp. Do you still have some as mentioned?? regards Russell.

 

Try this

https://www.jag-aire.com/


Cheers
DD

 

Russel,
I have plenty of the AC amps. I have made them for over 20 years. For the XJ6 However not sure if the same one is used in the XJS. If you find that they use the same one I would be more than happy to send you one. Free shipping.

 

Brian,

I have 4 used Amps in a box I'd be willing to send up to you from Ontario. I don't know if they work. You could try them and see. Advise is to leave the old one in place, just plug in a new one (ground too), and if it works, stuff in under the cheek panel and don't attempt to replace it in the same spot as original.

$25 plus post for any you keep. Mail back the rest.

Good luck,

Rob

 

@VWTechnician:

You are describing exactly what the A/C on my SIII V12 is doing....sometimes it works, but most of the times it does the opposite of what I want it to do.......

Will swap the AMP ASAP....

 

Thanks I'll see if I can find a part number....sense would suggest they should be the same.

 

Are your amps from XJS'S ???

 

the air conditioning amplifiers are the same part in the XJ-6 and XJ-S.

I removed one from a 1986 XJ-S V12 and it is identical to the one in my 1984 XJ-6.

 

ok this seems to be the part no. I need for my 84 XJS C45402

 

I need 2 of these, can anyone help?? thanks Russell.

 

I have checked the a/c system in the WS manual for a 84 xjs he. I don't seem to see a capillary style thermostat to control temp and compressor cycling??? Is it controlled solely by the ecu and sensors??

 

must be the Expansion Valve you are looking for? you can see it in the engine bay, behind the engine, at the center, sticking out through the firewall. They do tend to freeze the matrix if out of calibration. If you do not know the history of the Expansion Valve in your car, replace it, it is a GM part.

otherwise I have one amplifier from a 1986 XJ-S V12 Coupe. But I do not wish to interfere with those who have already offered amps to you.

 

I think what you're looking for is the Ranco Thermostat, under the dash, RH side of the main climate control casing. it has a capillary tube to the evaporator and will cut the compressor circuit if the evap core ices up. That's the only provision/method of compressor cycling.

You also have a superheat switch and fuse at the compressor which provide protection to the compressor....but that'll cut the circuit outright; no cycling function

Cheers
DD

 

this is the spare amplifier I have, it is identical to the one in my 1984 XJ-6, but came off a 1986 XJ-S V12.

I am not selling it, it is a spare for my car, but just so that you can compare.

 

Yes, that is the same unit I have in my car. Thanks.

 

Thank you, that's what I want to test first.My compressor is not cycling and eventually freezes up and stops pumping cold air. I still think I have a problem with the climate control as well, but want to start with the cycling issue first. Thanks again.

 

Here is a photo of the Jag AC Amps I make, fully tested and calibrated.
2 year warranty. Direct plugin.


A photo of one of my Jag AC amps

 

Your AC amp looks great!

Would you be willing to ship to the Netherlands and if so: for how much?