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I bought a 2003 Jaguar S-Type and the A/C works and cools very well. The problem with the AC starts happening after I drive the car for some time. The compressor clutch starts making a stuck noise and I can see the clutch visibly getting stuck, then it slips and gets stuck again on and on. If I turn the car on and idle the car for 15 minutes with the AC....... I have no issues. I could let it idle for a longer period of time, but I am not sure if the problem is with the compressor or something else. I have HVAC gauges and I checked the static pressure and they were good at 100 Psi. I ran the AC and looked at a chart to see what the 134a pressure would need to be if according to the outdoor temps and the pressures were good. I want to see if anyone here had this issue and if the problem is the actual compressor or something else.
Second issue has to do with the heater. The car had the radiator and reservoir replaced and the car stays at operating temperatures, but if I turn the temp up to 80 I do not get hot air. As if the heater core has no coolant running through it. Then in the morning the windshield is very fogged up and the defrost option doesn't work and it just makes the windshield even worse. Not sure if heat from the engine bay is escaping through the hood and fogging up the glass. Its so bad that its very hard to see in the mornings and it doesn't go away until the glass has warmed up. Can anyone here give me any suggestions or solutions to this issues.... I would greatly appreciated. I am fixing the car for my son and I bought the car for $1,500. The engine runs great and there are no issues with the transmission. It does have the plastics inside cracked and when locking the car it stays for some reason cycling the locks until it stops. Thanks everyone for the attention and help. If you need pictures or a video I will be more then happy to provide it.
No. For what I can see, the tracks on the PCB have dissolved.
This PCB-chip is dead as a Dodo.
And if the unit would be repairable, the tool of choice would be a soldering iron AND additional soldering tin - not a heat gun.
Those PCB chips are easily and cheaply available from cheap Chinese online sites - try Aliexpr.
Your heater issue sounds like a buggered heater control valve, P/N XR840091.
Your A/C issue:
> compressor clutch starts making a stuck noise and I can see the clutch visibly getting stuck, then it slips and gets stuck again on and on.
Let's see, if I understand this right: The stuck noise is the drive belt squeaking as it runs over a momentarily stuck compressor-pulley?
That sounds to me like a compressor, that is about to fail. I.e. it's on its way to have a permanently stuck pulley.
If that happens, the drive belt will squeak his "swan song" in loud screams - i.e. the belt will tear apart soon.
II have a feeling that the compressor needs to be replaced. This involves going to a specialized A/C-garage first for them to professionally de-gas the A/C system, as the R134a refrigerant inside is an environmental Ozone-killer, and must not be released into the air/environment.
Then: swapping compressor and all the seals of the A/C system - while you are at it - and then having the A/C-garage doing a vacuum test (to check for leaks) and then have the garage fill it up with A/C refrigerant and the appropriate small amount of A/C oil and it might be a good idea to also add fluorescent marker fluid for the next time, when you are looking for a leak.
Have you checked ac pressures will clutch engaged. Hi and lo side. The ac pressure switch may be the problem or elsvated high side pressures. If you replace the switch get a major brand. Been there done that with the cheapos. Need a little more ac info to give you a good path to follow
Last edited by scottjh9; Apr 18, 2026 at 06:56 PM.
Can you please confirm which transmission your car has? I ask because it’s possible your 2003 is actually a late 2002 instead. If so, there will be some differences in the climate control system.
The transmission is an easy way to check. Look at the numbers on the left side of the shift lever J gate. Early models had a 5 speed transmission. D = 5, so the highest number on the left is 4. Late models had a 6 speed. D = 6, so 5 is the highest number on the left.
Can you please elaborate on the AC clutch making noise? As Peter suggested, I bet that is actually the belt slipping and squealing. Details about a simple method to check for a slipping clutch can be found here:
If the clutch itself tests good, I’d suggest checking the belt tensioner. If that is good, I’d be willing to gamble your hard-earned money on a new belt long before convincing yourself the compressor is bad.
That same guide will also help troubleshoot the lack of heat. Keep in mind the heat in these cars is never stellar until the engine has warmed up quite a bit. Be sure to test the DCCV (Dual Climate Control Valve), also detailed in the guide.
As far as refrigerant pressures, don’t get too sidetracked chasing numbers. The troubleshooting guide explains how those numbers don’t always mean a lot and can steer you down the wrong path.
Ah, yeah, as Karl suggests:
Maybe it's not the compressor getting stuck at times, but it's the drive belt on the way out and not having proper grip anymore (especially when warm - i.e. after "you drive some time" - as you described it.)
Check the condition of the drive belt. Just look at it. Is it looking new, or can you see little cracks?
If the drive belt is the issue, simply change it.
If it were to fall off while you are driving, you'd be stuck and in need for a tow truck.
Also: Check, if the drive belt tensioner works properly, of if that is for any reason partially "stuck"...
Here is the link for the heater issues that I was sent a few months back. If you follow it through, you shoudl be able to work it out. It does sound like the heater valves/solenoids are stuck "off". They were on the car here too!
The reason i mentioned pressures is because an easy check is if the high pressure side spikes then the cut out is activated. Hook up a gauge and done. I disagree about pressures being a secondary if you know how to read them and use them. Without knowing pressure info i would have never cured my ac saga a few years ago that had all of us down the rabbit hole
Thank for everyone who has replied. I have been so busy at work that I haven't had much time. I will see if I can record the issue and sounds the ac clutch is making. I have done a couple of ac system replacement that involved the expansion valve, dryer filter and compressor. I bought a vacuum pump many years ago to vacuum the system and I have the gauges to test and refill. I have knownldege of static pressures and reading the gauges for reading according to the outdoor temperature. I think the compressor is going bad. I was just confused that it works good for sometime and after some time driving it just doesn't cool and the clutch starts getting noisy. I opened the hood one time when it was making the noise and I saw the clutch spin, stop and it looked like the clutch was sleeping or trying to engage, but it couldn't.
Regarding the heater .... I have to check the heater control valve to see in what condition it is and maybe replace it. In regards to the keyfob.... from reading online would have to be programmed by a locksmith. The foggy glass I will check if the cowl rubber seal is damaged and allowing heat from the engine to heat the glass un the morning causing it to get more foggy. I'll post back with videos and maybe photos.
No. For what I can see, the tracks on the PCB have dissolved.
This PCB-chip is dead as a Dodo.
And if the unit would be repairable, the tool of choice would be a soldering iron AND additional soldering tin - not a heat gun.
Those PCB chips are easily and cheaply available from cheap Chinese online sites - try Aliexpr.
Yes, I have seen the keyfob board online. The pricey part is that there is no way to manually configure it to the car security. I would have to hire a locksmith to set it up. From what I have read online for the 2003 model you need to have a locksmith do it and there is no other way.
I think the compressor is going bad. I was just confused that it works good for sometime and after some time driving it just doesn't cool and the clutch starts getting noisy. I opened the hood one time when it was making the noise and I saw the clutch spin, stop and it looked like the clutch was sleeping or trying to engage, but it couldn't...
Glad you're still here.
Fair warning: It's easy to convince yourself something expensive has failed. Take some time to work through the troubleshooting guide. See the link in post #6 above.
I'm still inclined to think you're hearing the belt slipping, as opposed to a clutch or compressor failure. You'll see a section on how to test for clutch slippage. It's also very important to check the belt tensioner.
If still convinced the compressor itself is locking up, try this: With the engine cold and key removed, try turning the face of the compressor pulley. That should give you a rough baseline of how much force is need to spin the compressor shaft. Next, duplicate the fault conditions so you hear the noise again. Turn off the engine and try to turn the pulley face. Hopefully the force required is similar.
If the clutch is indeed slipping, I'd suspect the relay in the control circuit. See my experience with this relay, detailed in the troubleshooting guide.
If the belt tension is correct, the belt may be glazed. Try a little belt dressing to improve the grip. If that helps, or maybe just changes the tone, then you'd know the belt had been slipping. A new belt would be in order.
Lots of little potential faults to investigate. Don't go into FullPanicMode just yet and start lobbing expensive parts at the poor car in hopes of a fix.
AC clutch getting stuck and heater not working
