2002 Jaguar s-type 4.0 No Navigation

Started blowing hot again on Drivers side.

Temperature outside 89 degrees south Texas

A/C pressures

Low side 35
High side 250

Changed last year 2015:
DCCV
Compressor
Dryer

A/C is cold when at idle through all vents. Sitting in the car and raising the rpms, the drivers side air vents begin to blow warm/hot.

There appears to be 3 hoses connected to the DCCV that run back to the dash/firewall. The top or nearest hose I can reach is hot with a/c on. I pinched off that hose to see if it made a difference and it did not change the a/c temperature.

I have not checked the wiring harness near the DCCV.
I did ohm the sensors under the dash a while back and they appeared to all run close to the same reading but not exactly. The readings did not appear to be different enough for me to believe one was damaged.

My question: Are the dash vents also controlled by vacuum? Could I have a vacuum leak?

Should I dig down deep to the wiring harness and check those wires? Can they be checked without disassembling the front end? Or do I need to tear it back down as if putting in a new DCCV?

 

Your high pressure is a bit too high and your low side is a bit low. Did you check each side (low/high) individually?

With your ambient temp your pressures should be in the: (don't quote me but these are pretty close)

45 - 55psi low
180 - 210psi high

All vents are controlled electronically with servo motors.

I would say the biggest issue right now is sorting out your high side AC pressure.

 

When I first checked the freon yesterday 9/10/16 the pressures were 42 on the low side and 300 on the high side. I thought maybe I had to much freon in the system and lowered it to those values above.

How do you check each side individually? Do you mean by hooking up the low side with the guages and not the high side and vice versa?

 

By "hot" do you mean you are getting heated air from the driver's side vents? or ambient air?
You may or may not have an issue with your refrigerant system, but if you are getting heated air with full-cold selected, you definitely have a problem somewhere between your climate control module and DCCV, or both.

 

300 psi on the high side is critically high and might have tripped your pressure switch to avoid damaging your compressor.

I always have both sides hooked up to the gauges but I always check one side at a time. (Low side switch open while I close the high side switch and visa versa)

 

I am getting ambient air.

 

Is your compressor engaging? Engaging intermittently?

 

Do I change the pressure switch?

 

yes the compressor is engaging. It is not cycling on and off from high pressure.

 

I'm going to hook the gauges back up and check each side individually. I will return with the results.

 

I hooked the guages back up and checking each side individually I get a slight fluctuation on the low side between 40 - 42, on the high side it seems to be stable at 230.

 

del

 

I found my AC chart. (Sorry about my previous figures being a bit off - I was traveling but wanted to contribute)

Ambient - 90 degrees

Low: 45 - 55psi

High: 250 - 270 psi

Discharge Temp @ center vent - max AC w/ blower set to high: 38 - 53 deg F (humidity less than 50% ambient) & 45 - 65 deg F (humidity over 50% ambient)...

Going through the thread again seems your recent readings - low side is a tad low and high side is low as well. (I would aim to get pressures dead smack in the middle of the range: 50 low/260 high @ 90 degrees ambient)

Needle should be steady with the compressor running. Of course if the clutch cycles the needle will fluctuate.

I would charge it up a bit more (should add refrigerant by weight) to get to ideal pressures listed above (keep tabs on ambient temp)

DCCV may be a contributor or a clogged orifice tube or expansion valve based on your initial pressure readings showing low side low charge and high side showing higher than range pressure...

DCCV would be the easiest to remedy. Replacing the orifice not so bad (discharge, recovery, vacuum, change orifice, vacuum again and recharge), expansion valve is a PITA to tackle.

 

If the ac pressures are correct, why change the orifice?

 

When you get your pressures to ideal range (again, your pressures listed are currently low) and you're not getting the correct temp out of the vents you have to start looking for causes.

The orifice and expansion valve are prime suspects or your compressor is toast.

 

This is the electrical connector to the DCCV. With ignition in the off position, I get 12.25 volts from the center red wire to the brown/green wire and 5.22 volts from the red wire to the brown/blue wire. Then I turned the ignition switch on, then I turn the drivers side controller to cold and the passenger side to hot, then check to see if left or right side of connector had voltage. Then I switched the controllers to drivers side hot and passenger side cold. I get the same voltage reading as if there was no change with ignition on. Is this procedure correct?

 

not sure if procedure is correct but is there any sign of coolant on the connector or the DCCV? I only inquire as the connector looks wet..

 

It is only damp from me removing the radiator hose above it. The DCCV was installed last year.

 

Shouldn't both voltages be the same from side to side? I'm thinking AC module in the dash is bad but hate to change it if I'm wrong with my diagnosis.

 

If it's the module you can spot the burnt traces with a quick look-see, before purchasing a replacement to change it out. I thought the 2002 had more hoses than 3 to the DCCV. 03 and sub have the 3-hoser. There is a diagnostic how-to for the DCCV/CCM linked in here somewhere....well, probably several...but a quick search on climate control or DCCV will probably turn it up. My experience with a burnt trace in the CCM on the 05 is that I couldn't tell beans about how it was supposed to be working by checking voltages at the DCCV 3-wire connector.