Hi together,
it’s getting warmer outside and could still not solve my aircon problem.
I bought the car with non-functional Aircon. Tried to recharge didn’t help. Main dealer suggested to the previous owner to change the compressor. What I finally did and recharged and cleaned the system again, but still no cold air. System holds pressure. Everything is tight.
SDD says, no connection to compressor, so I checked fuses and obvious electrical lines. Nothing helped.
So my question:
1. Are there any cable connectors (like the ones from the S type behind the front bumper) prone to go bad?
2. Is the CCM from the V8 interchangeable? I have my own sdd to Programm it and an XJ8 which I break
3. I bought a PWM generator, which voltage should I send through to test the compressor?
4. Does anybody have an electrical schematic of the 2,7d 2007 model?
5. Any other suggestions?
I never had any problems with the climate control with the V8s whatsoever so I a bit confused So many many tanks in advance for any help.

best regards Hajo

 

I can only give you an answer to question 4.

You can find the schematics here:
https://www.jaguarforums.com/forum/x...enance-246865/
(Chapter 4)
Depending on the month your car was built, you will need either the MY2006 or the MY2008 schematics.

Best regards,

Thomas

 

go across the VD valve with backprobe pins. look for a varying voltage anywhere from 4-9V, it's being pulsed to ground. if yes, you can roll the dice and replace the valve with aftermarket, it's sold for land rover lr3 7seu16c or buy a new denso compressor. i've done a ton of these on a lot of brands

 

I changed the compressor already, it usually should come with a new VD valve? Or are the aftermarket compressors sometimes not working?

 

"Aftermarket" compressors? Should work, right out of the box, but might have a higher risk as to shorter life-expectancy than a Denso. Can't tell if you can't even get it to run.

What did you use?

 

Check the Pressure cut-off switch

Pressure Cut Off Switch
The pressure cut off switch monitors the A/C compressor discharge pressure and communicates with the engine control module (ECM). The ECM will interrupt A/C compressor operation in the event that
the pressure cut off switch indicates high system discharge pressures. It is also used to sense no or low charge conditions. If the pressure is below a predetermined value for a given ambient temperature, the ECM will interrupt A/C compressor operation.
· The pressure cut off switch is mounted on a Schrader-type valve fitting on the compressor to condenser discharge line.
· A valve depressor, located inside the threaded end of the pressure cut off switch, presses on the Schrader valve stem and allows the pressure cut off switch to monitor the compressor discharge pressure.
· When the compressor discharge pressure rises to approximately 2,896 kPa (420 psi), the ECM will interrupt the compressor operation and disable the compressor.
· When the pressure drops to approximately 1,724 kPa (250 psi) the ECM will enable the A/C compressor circuit.

 

What @ctsemicon just said.

"Sounds as if.." you've done enough A/C systems to have the skill, adapters, and gauges, yet:

- I'm not clear as to how you expect to have gotten a proper charge into the system if you had not already grokked how to over-ride the low pressure disable so as to force compressor run and get to where pressures would satisfy it with manual over-ride no longer needed?

- Could it be that the "real problem" is simply that all the components work, but you did NOT reach a proper charge?

- And/or that it had previously failed because of failed sensors.. and you haven't yet replaced the guilty one(s)?

System had been non-functional for "a while"? Closed & at least partially charged or 'open'? You purged as well as pulled vacuum? You had also replaced the dryer?

Lots of bad things can happen in a partially "abandoned" AC system left to deteriorate. Most especially if the prior minder had been dumping glorified snake-poop into it - or solvents sold to "soften" seals into "born again" wish-fors - in hopes of sealing a leak.

D'you have Guage readings? Record of the mass of refrigerant used?
If it went in, did it STAY in? Nine cent "o" rings routinely ruin folk's days.

All "Capt'n Obvious" stuff, but it IS the 'obvious' as most-often wastes our time and money - - most especially when a prior owner left a system faulty for any significant length of time.