Hello everyone, I am very happy to have finished the restoration of my old 1995 X300, we did an impeccable job both on the interior and on the bodywork... The only thing that doesn't work after 10 years is the air conditioning compressor...
I refilled it with 650gr. with R134a but the belt turned idle trying in vain to turn the compressor...! What do you suggest, can I try to dismantle and overhaul the compressor which is evidently blocked after 10 years of inactivity, or should I look for a new compressor...?
What model would be compatible with the original MNA 7300AB...? Could it be Denso mod.471-1350...?
Are there other reliable compatible brands?
Based on your experience, should I also replace the dryer...?
Thank you very much for the usual, precious and affectionate support...?
😉

 

Yes on replacing the dryer , and reverse blowing with air out the thermoexpansion valve while freon lines open ( old dryer beads get loose and clog effecting the cooling performance )

The compressor clutch that can be replaced on car without removing the compressor can be bad and can be tested with a meter for resistance

The clutch will not engage if freon to low ( protection )

As you rebuild the system there is an easy front climate control panel bite test with codes ( Youtube video made by someone )

" The belt turned idle trying in vain to turn the compressor "

With the engine off and I assume Key off the compressor clutch should not be energized or engaged to the compressor

There is a good parts source in the US otherwise the clutch is a common part ( not Jaguar special ) easily available

See video part 1 and separate part 2

Automotive FAQS about Air Conditioning Repair by Century Auto AirConditioning of Tucson Arizona, AC Parts Services and Hoses, www.centuryautoair.com

The parts section does not seem to be working today

 

Thank you Parker, you are an inexhaustible source of information and inspiration for all of us...

 

I learned from everyone that contributes their knowledge and experience on this website

 

You might be able to read the clutch without it running by the bite test

Video and manual and codes coming

14-10 Climate Control System DTC.pdf (jagrepair.com)

 

The clutch center shaft bolt ( 10 mm ) has to come off with an impact gun ( maybe a cheap electric one is strong enough ) there is no other way to hold the shaft unless the shaft / compressor is mechanically jammed / broke which hopefully is not the case

There are some tricks to the belt lower idler pully / squealing bearing tension loosening to get into later but first do not strip the 4 sided head loosening long bolt that points straight down , the long tension adjustment bolt gets very rusted up being exposed to the elements . The pulley is creap and recommended to be replaced while there , common Gates manufacturer part # X easily available

If 10 mm bolt not coming off you can remove the compressor and take to a shop and they can remove with a stronger impact gun ( !0 mm impact rated socket supplied if they don't have one as you ask first ) and you can do yourself the rest of the overhaul work yourself with the final install ( enough final bolt torque ) of the 10 mm center bolt back at the shop

There was a TSB or something on a change in freon PEG oil on assembly

In starting the car from a " dead " car the clutch should not be energized / engaged as this compressor would be a drag on starter rotation

There is a low 2 Bar switch that protects and de - energizes the clutch and you may be able to maybe disconnect the switch to engage the compressor

researching , ..................................

This is the 4 wire freon pressure switch which the upper 2 wires drops out your clutch ( pressure too low and too high overpressure / freon charge / fill too much does this )

Fuse # 8 / 10 amp and # 10 / 5 amp both right engine bay fuse box

Large # 3 right relay , left # 3 large relay should be the cabin heater auxiliary water pump

The large relay should click in your fingers to close ( when you turn climate control panel to A / C on ) and engage the clutch ( you have relay swapping options as this relay # LNA6706AA is same for headlights and fog lights )

See item # 1

Genuine Relays For Jaguar Xj 1995 - 1997 (from 720125 To 812255) (x300) Classic | Jaguar Land Rover Classic Parts

You don't need to concern yourself with the mod on the 2 wire freon pressure switch which is a TSB as this does not affect clutch just radiator fans

 

The clutch coil item # 33 ( NPA - 101 ) if needed should be a common available item as Denso is a common compressor on many cars

Parts page on Centuryair still not opening up but cheap parts

 

Be *very* careful and patient with the drier lines. The threads of the high pressure lines like to seize onto the drier. Just a word of caution is all. I believe you’ll need two 19mm wrenches. Good luck!

 

" The threads of the high pressure lines like to seize onto the drier "

Would heat and penetrating oil help ? the oil may not be good for the replacement o- rings

Reassemble with mineral oil to make the threading easier to not cross thread ?

 

I think the heat from a small propane torch and penetrating oil will suffice. I only say this as a precaution because I dislike being caught off guard. Let’s hope that 10 years of not going down a road with water spray getting on the threads will be in this man’s favor and won’t be an issue at all. As for most X300’s, that’s not always the case. Sometimes it gets so bad that I have to hold the nut of the pipe still while I turn the drier. If the threads are bad enough, I’ll use antiseize as oil isn’t good enough.