My AC has never worked since I got the car.

I pulled the codes from the climate control unit and I got a code 23. I ordered and replaced the switch with a new unit from fcp euro and no change still getting a code 23 or sometimes after clearing it shows 0

The ac compressor is not spinning the pulley is just idling.

I know the switch has 5 wires. I found this:

1 = ECM connection for high speed
2= Ground
3 = ECM connection for low speed
4 = Power from ignition switch
5 = A/C controller connection

from this thread https://www.jaguarforums.com/forum/x...switch-272846/

I found the ground on the row with 3 wiress/pins in the middle but nothing saying what I could see on the other pins.
What voltages out side of the 12 volts on the power pin should I see?

What orientation should the harness connector be at and what are the prin numbers/locations?

Is there a way I can toss a multimeter at the switches I have and test them to see if they are good/bad?

Under code 23 on the guide (2001 XJ Climate Control Fault Codes.pdf) it says switch or harness issue refer to PDU. What is the PDU?

I promise I have searched.

thanks in advance!

 

You probably don’t have any refrigerant in the system. One thing that I’m familiar with is that high pressure switch, when you unscrew it, that schrader valve that’s been stuck in the open (down) position (just beneath the pressure switch) for the last 24 years will continue to be stuck in the open position unless it’s been replaced at some point in time. This means when the high pressure switch is removed, the refrigerant removes itself from the open valve. So if you replaced that switch and the sound of escaping gas didn’t come out, chances are it’s already out. That’s funny that code 23 is displayed twice in that link. One for defective switch and the other for low refrigerant charge. Chances are quite high that if there truly is no refrigerant in the system, at a minimum every o ring will need replaced and the receiver/drier will also need replaced if it’s original. Trust me, I know how incredibly frustrating, difficult and time consuming it can be to try and track down a refrigerant leak can be. I would advise against getting a can of “refrigerant” especially with the sealer in with it at the parts store. The issue is that there’s waaay more oil in those cans than there is refrigerant and you’ll over oil and under refrigerant charge your system. However, I’m pretty sure that you can order those cans of refrigerant only from online. I haven’t seen them in the stores personally. Another thing you can do is remove the compressor relay and use a heavy gauge wire to jump pins 3 & 5 of the relay holder to see if the compressor clicks at all. If you run the engine and have A/C button on, jump the relay and the compressor should come on. DO NOT keep the jumper on for more than about 5-10 seconds and the fans don’t run. The reason is that if it does have refrigerant, the pressures will skyrocket IF the fans aren’t on and something will blow as the rubber hoses are old. If the fans come on, it should be ok to run for a short period of time for testing purposes.

 

So when I was replacing the switch i used a screw drive to test the valve. It did release pressure. also pressure is in the 30 psi range on the low side according to my AC Pro PROFESSIONAL quality guage...so +/- 15 psi is my guess. Where is that relay? I have checked I think it was fuse 8 and 15 in the engine bay fuse box (3 whisky shots in ATM)

I read the posts about oil and refrigerant lesking from the valve and through the bad switch and into the harness. None of that is seen on mine.

every pin on the harness side besides ground is showing voltage...i think min 10v to 13.5v(guessing the acc power when the AC is on)

 

Coming back to this!

So I pulled a vaccum on the system and then added refrigerant. I can get to 60-ish psi showing on the high and low side but the ac compressor seems to refuse to kick in.

I usually get a code 0 on the hvac conter and sometimes 23.

Were can I jump the compressor to se if it turns on and rasises pressure on the high side to see if i have a compressor problem or an electrical problem?

 

From the switch connector. Short thogether pin 2 and 5. That tells to the ecm that car has atleast normal pressure. Does the code go and stay away now ? Measure the voltage from pin 4 against pin 2. Do you have full voltage when engine running ?

 

Do you have the pinout in relation to which pin is which to make sure I am checking the correct pins/shorting the correct ones?

I found a relay map pointing to R1 in the engine bay fuse box being the ac relay and it is clicking when i unplug it and plug it back in.

 

See page 114 for freon pressure switch code 23

X300 00/E COVER

 

that url appears to be broken

 

Pinout was printed to the connector if I remember right.
Wire colour to the pin 2 is black, pin 5 blue, pin 4 white yellow, pin 3 red white and pin 1 white blue.

 

Using that I shorted those pins and no change. the clutch is not engaging.

If i unplug the hartness form that pressure switch i get a code 23. if i clear it code 23 does not return

if i hit auto in code mode i see 0 if i press recirculate it shows 20

I do not see a code 20 in any list i have found for the hvac codes.

If the R1 is the ac clutch relay it is energizing the clutch it just isnt engaging or the clutch is bad.

I have roughly 2/3rds of the 600-700g charge in the system.

High and low side are the same pressure. after the car idling and guessing from the heat soak It got up to 110psi on both sides and never kicked in. High side never climbed high than low and i never saw the compressor enggage.

I am guessing my next step is to check to see if the compressor is getting the 12v to energize the clutch. if it isnt since all the fues are good and the relay clicks it would be a wire break somewhere up stream.

If it is getting 12v are these clutchs replaceable or am i just to replacing the dryer and compressor?

 

The good clutch coil when read with a meter is about 2 or 3 ohms resistance and a bad one will read infinite resistance , you may be able to change the coil ( if gets to it ) without disturbing the compressor or the freon lines charge

A too low or too high freon pressure switch reading ( if at fault ) will drop out clutch

Double checking the 2 or 3 number as pulled from my mental museum

in the end the clutch should receive 12 volts from the clutch relay ( socket 5 ? )

clutch relay click with your fingertip on it ( verifies correct " to go " command ) or relay swap ?

May be able to hear compressor clutch engage as a clack sound

Looking for convenient meter test points

 

For clutch verification place 12 volts on socket 5 of the clutch relay EM52 and feel or hear clutch clack , you can actually use a battery charger as the coil has resistance and will not blow

To verify relay is getting correct command to close ( verifies freon pressure switch ) look to see the socket 2 is getting a ground on clutch relay EM52

 

Pressure switch works in three stages. Shorting out pins 2 and 5 tells to the hvac system that there is nominal pressure in the system, Doing this should kill the 23 faul. If not, there is fault elswhere. EM52 controls the clutch. Instead of jumping external voltage to the wire. Jump wire from pin 3 to 5 in relay socket as Parker7 relay image gives. Do not permanetly stuff wire to it. By toutching either end to the pin wil give tiny spark and loudish clank when clutch engages and disenages. Do this key on engine not running. Put a weak current test light arcoss pin 1 and 2 to see if hvac system controls the relay or not. With this engine needs to be run.
If clutch does not click use the test light against ground and measure from the pin 3 is there voltage. If not check fuse 8 in ENGINE MANAGEMENT FUSE BOX.
If clutch is making sound but there is no relay control. Issue is elswhere.

 

There is that one and possible a 2nd fuse or power source for the clutch relay to work passing power to the clutch

Would have to research

 

I was looking at the incorrect relay. I also found a bad fuse that was somehow giving me continuity across the posts.

Now I am not getting 12v to the constant hot end of the relay. That is a red wire with a white stripe that I believe comes from the pressure switch. I am going to have tocheck the harness at that switch again

But I did confirm my clutch does engage

back to the pressure switch

 

This is exactly why multimeter should not be used as fuse tester.

 

So took the car for a short drive and i am guessing it may have just needed more RPM because on the drive it kicked in.
I think it still needs some gas added but i was seeing lower than ambient temps

 

Heat of the engine will bring up the heat in engine bay. That will increase the gas pressure. Usually r134a gas hvac's are tuned so that they will not go under +5 C. That is enough cold air to have a cold.

Do put more gas to it.