jagR2004,

'Jump' the compressor relay, & see if the pump runs. If it doesn't, the thermal cut-out has probably crapped itself. The cut-outs are 'electronic' & not repairable, but search this Forum and/or a Range Rover Forum for info as to where you might find an alternative to buying from Jaguar. I believe the compressors may still be manufactured by a company called Thomas'.

If it does run, disconnect the output line from the compressor & put your thumb over the nipple. If it labours under the load, it is still operating, although not necessarily at full capacity. If it doesn't labour, the compressor piston rings are worn out, and you will need to rebuild/replace it.

The compressor's role is to maintain compressed air in the reservoir, and the springs are fed from the reservoir rather than the tank. There was an earlier thread about this, & member u102768 knows more about the primary operation than I do. As I understand it, the compressor should kick in if the reservoir is unable to supply sufficient air to get the suspension off the stops. The other member whom I can suggest you communicate with is Brutal. He is pretty 'cluey' about many of these things.

Cheers,

Languid

 

Which almost certainly means the the regulator on the alternator is what is actually faulty, not the alternator itself. It's clearly working well, producing current, but the voltage is out of control. By replacing the alternator in total, you are actually throwing the baby out with the bath water.

Cheers,

 

Sorry,
Don't know how that reply got into this thread. I was reading about an alternator overcharging problem when I wrote up the response. Now I cannot even find that thread!!

I just hope that the writer of the alternator thread manages to find this.

Cheers,

Languid

 

Posted in the interest of correctness.

There is no "thermal cutout." The ASM avoids overheating the compressor by limiting the duty cycle.

The reservoir and the tank are one and the same.


I post here to share information and to solve problems. If my posts appear abrupt to you please do not read my posts.

 

OK, fair enough, but it would be nice to ocasionally see a few diplomatic phrases to smooth things out a bit. Not everybody who comes on here for help is expert with spanners, or up to speed on modern car systems, so they are not capable in knowledge terms of deducing what could be wrong with their car.

For me, I used to be good with spanners etc, paintwork, lead loading (older Jags only), but the modern systems and electronics are beyond me. I try to read all about these things if I can find the info, but the car companies do try very hard to keep things in house, at least that is my experience.

Hope you are well, and car also !!

 

Sorry, I don't do sugar coating. The plain, direct, simple, unvarnished truth. You will never see me short with someone unless they ask for it. I am eager to help.

I try VERY hard to make sure what I post is correct. If I am not sure, I will tell you. I expect the same from my fellow man. Too much "my brother-in-law who is a tech" second hand hearsay lately. This muddies the waters and helps no one. When I had my suspension problem I read everything I could get my hands on and listened to everyone. I now know more than I ever wanted to know about the X350 air suspension.

I am sure Languid is very knowledgable about Rovers and is one hell of a nice fellow but he tends to assume that Jags are the same. Not always true. Before I countered the remark about thermal cutouts, I went to my shop and looked at the pump disassembled on my bench to be sure. There is no cutout. One heavy gauge wire direct to the brushes.

I have no doubt you both are fine fellows and I would buy you a pint anytime. I mean nothing personal.

I am sure my no nonsense approach comes from my career as a fighter pilot and airline captain. Having the correct dope is crucial. I expected and welcomed a challenge of any misinformation I passed as gospel. Every Brit pilot I ever met was the same way. Airplanes can be unforgiving creatures. Especially when people are trying to kill you. The m-fers weren't good enough to get me.

Cheers