Hi,
I evacuated my ac system over night. Using manifold gauges I put in 20 oz of R134 but the clutch still hasn't engaged. The lower pressure side is at 75 while the high pressure side is at 140. Should the clutch have engaged by now? How can I bypass the clutch switch to turn on the compressor?
Thanks,
Jomo

 

See page 17 for relay X which can be swapped with a like relay part # 7606 ( a headlight or fog ) and page 21 for fuse Y and Z

X300 1996 LWB.pdf (jagrepair.com)

 

You can jumper with a heavy wire socket 3 to 5 to directly power the A / C clutch

The clutch coil can be changed without removing the compressor or removing the freon lines

There are Youtube videos of the Denso 10PA - X compressor clutch replacement on other car other then a X300

Do not round out the compressor pully tensioner adjustment long bolt as will probably be frozen stuck

 

Have you performed a A / C system bite / self test on the cabin climate control head ?

It is on page 110 of the Jaguar703 climate control Doc

There is a Youtube video of someone doing it on a X300

T703 BOOK (jagrepair.com)

 

Important ,

Before running the compressor , do you have PEG oil in the freon lines ?

Some recharging cans are just straight Freon and no lubricant for the compressor

When you service the system the compressor should be running least it hydraulically damage the compressor

 

Not sure why the pressures would read like that if the compressor was not working at all. If it was not working they should be near equal, or possibly higher on the low side (initially, before compressor engages), as that is where you should be charging it from.

I think the compressor should come on with 20 oz in, at those pressures. the system capacity is 36oz.

If not, you can jumper the compressor to turn on from the connector at the pressure switch, R. side firewall. Jump blue/black wire with black/pink as seen in the diagram above.

 

I got the clutch to start spinning every time I turn on the ac but no cool/cold air--nothing. The clutch is staying on. I bypassed nothing.
Yes, I did put oil in the system.
What should I check now?

 

The outside portion of the compressor pully and clutch will always spin but when engaged the inter portion and shaft into the compressor will be coupled and spinning

With the engine not running

You can put a meter on the single wire clutch connector and you should see some resistance like 10 - 30 ohms but not infinite or very high

You can place 12 volt power on the clutch single wire connector and hear the clutch thump or click

The 12 volts can come from anywhere like a battery charger yellow positive lead and no need for a fuse as the clutch has resistance

If the clutch is bad no harm will be caused in these test

 

I looked more closely at the movement of the clutch and it is shot. It just wobbles way too much. Maybe a bearing? If I change the clutch should I just replace the ac compressor as well.

 

I now see why the clutch is wobbling. The bolt in front of the clutch is not there. Hopefully, replacing this bolt will fix everything!
Can some extremely nice person please tell me the thread size and length of this bolt. Please!

 

The center bolt is 10 MM and high quality and is put on with a impact gun

Probably taking it to a A / C shop they can do it on car as long as the pully belt is in place to hold the pully from spinning

You might want to put some bolt loosening compound on the long tensioner bolt as this is usually stuck and they would charge a lot to get your belts correct before leaving their shop

I had to remove the tensioner assembly and work it on a bench to free up the long tensioner bolt

Do not round out the 4 sided long bolt head , you can pound on a socket of a certain size and use the square normal receiving hole in a ratchet

There is nothing special about the idler pully and a common Gates of a certain # works and you can find them at the auto parts store

See item # 2

Genuine Compressor Belt Tensioner-3.2/4.0 Litre (3.2 Litre,4.0 Litre,4.0 Litre (california),4.0 Litre Supercharged) For Jaguar Xj 1995 - 1997 (from 720125 To 812255) Classic | Jaguar Land Rover Classic Parts

 

The center clutch bolt is not shown on a parts breakdown but a good A / C shop can source one for the common Denso 10PA series compressor assembly

The one on the X300 is either a dash 15 or 17 so 10PA - 15

 

Would the 95 xjs have the same bolt?

 

If it's a Denso compressor maybe

It is a special high strength bolt with short shank length and a chamfered head or a curve corner between the head and shank , not a sharp corner

To spin the long tensioner bolt the idler pulley center bolt must first be loosened as the threaded block behind it must lose it's grip on the tensioner bracket that can be removed from the engine block

Without loosening the idler pully bolt the other long bolt will be really stuck , ask me how I know

I used heat on the threaded block and worked it back and forth until it cleaned itself out of rust , this on a bench