Never let it be said that due diligence is a waste of time. I'll give the punch line now, the compressor worked. Here's the longer version. I connected the jumper cables to my Durango and had the engine off. I ensured I was getting power to the other end by the use of the multi--meter. I removed wheel and the inner wheel well shroud and immediately saw the red/black wires going to the compressor. I detached the wires from my multi-meter and connected them to the jumper cables. I used another multi-meter to ensure I was getting 12v from the newly connected leads. After several minutes of fiddling around trying to get one on the neg and one on the pos and going through a few different flashlight changes to find one that would shine into the required area, I fumbled repeatedly as I didn't want to cross the tips or touch the wrong stem on the compressor. I finally abandoned that line of thinking and connected the harness back up and use the pointed ends of the multi-meter wires to pierce the red and black lines going into the compressor. Well, it started to chug VERY slowly and the wires became quite warm rather quickly. I removed them as I believe the compressor would run much faster and run properly if it had the sufficient power going to it with the proper gauge wires. So, it looks as though I have a quandary to which the likes I've yet to see. It's not the relay and it's not the compressor...I need to see if the tech manuals I bought online have a wiring schematic to help me determine where in the heck the break in power is. It's after 1AM in Virginia and I have to be up in five hours. I'm going to call it a night. As it's almost dawn in the UK, maybe some of you folks will get to read this before some of the folks here and will have some ideas as well. Thanks to all and for the push to check it first!

 

The thought did strike me that you have a bad earth (US=ground). There are three earthing points at the front of the car. Looking from the front, they are behind the headlight units, below the plastic cover above the radiator. The one earthing the compressor should be the one on the right. However, I'm not sure that is where the compressor is earthed. It's no good getting 12v sent to the compressor if it can't get out once its got in ! A black cable indicates an earth, so it must fix to the bodyshell somewhere.

Anyway, that is my tuppence.

 

Yes if trying to power the compressor with a battery charger they do not provide enough current, it will turn but could mislead you to think it is underpowered, but instead use the jump leads (or big wires) off the car battery and it should spin nicely, as fraser check those earth points in the front too seems to be common on the Jags.

compressor relay and fuse also big on the list for your issues, the issue can be i have heard is the car sometimes needs to move before the compressor kicks in, or is not the case?

Andy

 

Now that you brought this to light, I definitely agree that I need to locate the earth for the compressor and ensure that it's not come lose, disconnected, etc. Thank you for another idea!

 

Andy,
Thanks for the input and I agree that the battery charger would not suffice. That is why I chose the battery from another vehicle. It’s a completely separate power source and would be a clean source of 12V. The multi-meter wires were quite thin gauged and that explains the influx of heat as rapidly as it was to them after the connection was made. Through past life events, I’ve learned that larger wires carry more current with more ease. For example, I had a friend trying to jump start another car with some mighty thin gauge jumper cables and it did not allow the car ‘s engine to turn over rapidly enough to actually start. I recommended using the REALLY large gauge jumper cables that I bought (for just such an occasion) and he reluctantly agreed feeling that his should have done the job. Surely as the sun will rise, the car started right up with the larger gauge cables. My friend ditched his old ones as soon as he obtained larger gauge cables. I’ve used them several times. Even one time to pull a pick-up truck out of a ditch with my Durango. They are quite robust cables.

My next task is two-fold. First, I need to find the grounds (earth) and determine their worthiness. If that does not bear fruit, secondly, I need to use larger gauge wires to connect to the compressor to determine if it will run with much more vigor and tenacity than the 1AM test last night as it chugged along quite slowly (similar to my friend’s car did as I mentioned earlier). I will try to paint a mental picture. Think of how a compressor normally sounds as the piston goes back and forth rapidly, similar to an air brush compressor that I used with my Father as a child in his Taxidermy business painting the various animals that came in. It sounds like a dull thudded machine gun. Well, last night, mine sounded like a dull thudded semi auto rifle; “thug, thug, thug”, etc. As I didn’t want to damage the multi-meter wires by melting them, I did not allow them to stay connected for more than a few more seconds of the dull thug.

When (not if) I get the compressor running, if it’s not producing adequate air pressure, then I feel the rebuild kit you offer will be in order. I have to say that the tutorial on here and Edd China of the Wheeler Dealer’s show have really put my mind at ease as to the simplicity of this procedure. I routinely strip small engines and repair them (lawn mowers, etc) along with a replacement of the transmission (gear box), transfer case, rear drive shaft, and all U-Joints in my Durango a couple summers ago in my driveway, I think the rebuild should be a breeze if it’s necessary. Getting to that point has become more of a chore than I EVER anticipated though. With more thought, testing, and the help/support from this forum, this too shall be beaten! Thank you all again!

 

Good morning, Jason!

Good work proving that the compressor motor will run. The resistance of the thin-gauge meter wires probably wouldn't pass sufficient current to run the compressor full speed. As abonano has mentioned, the air suspension relay is a 40A unit, which is about the highest current rating I see in typical passenger cars, so the compressor must draw a pretty hefty current to merit a relay with that capacity.

Regarding the Electrical Guide, I think the Captian Jaguar website is still down, so PM me your email address and I'll send you the manual in pdf form.

The ground for the air compressor is behind the front left headlamp (left when viewed from the driver's seat). If you have one, a ratcheting box-end wrench ("ring spanner") is convenient for removing the 13mm aluminum nut. Clean the threaded stud, ring/eyelet terminal on the wires, and flat surface of the nut with zero-residue electrical contact cleaner spray and a brass-bristle brush. Do not use sandpaper as some recommend as this will leave fine scratches that promote future corrosion. You want a nice gas-tight joint when everything goes back together. Take care not to overtighten the nut: at least one member of this forum broke the threaded stud off of the inner fender and had to drill and tap for a new ground point, which couldn't have been any fun given the limited access due to the proximity of the headlamp assembly.

You can test the relay by applying 12V to terminals 1 and 2 of the relay and using your meter to confirm continuity between contacts 3 and 5. There should conversely be no continuity between 3 and 5 when you remove the 12V from 1 and 2.

At the relay base in the fuse box, there should be 12V present at the socket into which terminal 3 of the relay fits. Based on a quick peek at the schematics, 12V should be present at that terminal at all times - it comes from a battery power buss in the fuse box that is separated from the battery only by a 175A megafuse. The 40A air suspension fuse, Fuse 6, is after the relay, on the Red power wire to the compressor.

The air suspension relay is switched on by the Air Suspension Control Module (ASM) via the Brown/Red wire at terminal 2 in the relay base. Relay terminal 1 in the socket should be at ground at all times.

Hope this helps. PM me your email address and I'll send you the X350 Electrical Guide.

Cheers,

Don

 

Mr Don,
Good Morning right back to you, Sir! Mine came too early today, but I thank you for the kudos and the motivation provided to actually learn what needed to be done, even if it was after midnight on a weekday when I finally got to it! lol I have sent the PM as you suggested and am looking forward to getting to it. 5PM can’t get here soon enough today!

I will be checking the ground, assuming I can locate it swiftly and making my best guess as to its proper functioning or not and do my best to get her clean. I did notice that there was no mention of dielectric grease. Was that intentional? Should I NOT use it or would it aid in the prohibiting of future corrosion as it does for battery terminals? What says you? Following that, testing the relays as you suggested is next on the menu.

With the tenaciousness of folks like yourself, I’m confident we can find the solution to this, or, at the VERY least, have a bevy of reports & test results (even a failure is result) to provide the Jag dealership if it gets to that point, which we all know why I’m hoping to avoid that. First of which is my male machismo and thick ego smeared with a healthy layer of pride, not to mention the overwhelming costs for them to conduct the same test that I’ve already done. My chin is STILL held high and I will drive on with this until my last string has snapped. But, as long as my rope is holding and I’m at the end of it, I’m going to tie a knot and hold on for dear life!

 

Hi Jason,

Dielectric grease is great if you apply it only after you have replaced the wire terminals on the threaded stud and retightened the nut. Since dielectric grease is an insulator, in my opinion it should not be applied to the wire ring terminals, stud or the nut's flat bottom. It should be applied to the outside of the complete assembly after you put it back together. Below is a link to a photo album I did on ground maintenance, using photos of grounds in our '93 XJ6. I've taken photos of the engine bay and trunk grounds in our '04 but haven't had a chance to upload them yet. The principles are the same:

Welcome to Jag-lovers - Members Photo Viewing Page

Cheers,

Don

 

Well, I didn't have them in my arsenal of tools, but as I work 2 miles from a Harbor Freight, I stopped by at lunch and picked up these little gems! Looks like I’ll be able to make this a bit easier on myself. I needed a good excuse for them and now I have one! And, I thought, I’m picking up the metric, I might as well get the SAE while I’m there! Makes perfect logic to me… lol

 

Thanks and I will remember that. I picked up a good set of brass brushes as well when I was at Harbor Freight as my old ones were quite tired. Also, it's going to be sticky this afternoon working on the Jag... (see attached pic)

 

101 !!! And I thought 95 in Nashville was hot! But I'm sure it's a "dry heat" in Chesapeake, right??? :-)

 

About 20 miles from the Atlantic, I can only wish it were damp heat!!!! lol

 

I removed the ground and used a new brass brush to scrub all the wires and the post which were in very good nick before I got to them.

So then I had an interesting and not so interesting testing results. I used a much larger gauge wire and secured it to the jumper cables and stripped the lines on the compressor to make a good connection. Using the Durango battery again, I taped everything up so as to avoid any wires touching where they shouldn't. Having the plug out of the compressor, I connected the cables to the battery, started the engine on the Jag (JIC) and then briefly plugged the compressor connector in and it kicked on like it should. I disconnected it rather quickly and then started recording, but the video of 90 seconds is too large to upload, so I'll have to do my best to describe the results. That should be rather easy though as I plugged it back in and it ran just fine for the full 90 seconds until I disconnected it, turned off the engine and then I disconnected the cables from the battery and proceeded to remove the wires from the compressor wires and tape them all up securely.

I have yet to go over the schematic as I've been doing the above and just had a moment to sit and type this.

I've swapped all the relays with known working relays, swapped the fuses with known working fuses, cleaned the ground and ensured the compressor is functional. I checked the wire connectors on the top of the front damper (which are new) and they look top notch. The pins inside them are straight and appear to be connecting properly. The CATS Sys Fault reared its ugly head again off an on today.

The Air Sus Fault has yet to show amber, but I'm assuming it's only a matter of time. As much as I HATE to say it, I am admitting defeat as I've reached the extent of my knowledge and capabilities. Very much to my shagrin, I'm going to have to visit the local Jag dealership. Unless I can see something in the schematic that jumps out at me, I'm in Barney (trouble). Thank you to all for your guidance, patience, and assistance thus far. I have learned MUCH in a short period of time and I owe it to you. Goo night and good luck.

 

Hi Jason,

Visiting the Jag dealer or a good independent Jag mechanic with the capability of reading the proprietary Jaguar codes is hardly "admitting defeat." It's just one way of acquiring the information you need in order to accelerate the process of resolving the malfunction and minimizing the cost.

Another option exists, and that is to acquire JLR SDD software and a suitable pass-through OBDII cable such as the Drew Technologies Mongoose or similar and set up a laptop running Windows XP Pro 32-bit (I'm running it on a virtual machine within a Windows 7 Pro 64-bit laptop). With this setup, you can scan for the Jaguar codes yourself. Search this forum for information on sources for the software and pass-through cables and how to set it all up and make it work with minimum problems (some issues are unavoidable, but tolerable).

You really do need those codes, which may save you a lot of time and frustration (I can't remember if any of us have said that before....).

Cheers,

Don

 

It çertainly stings a bit less with that point of view. I am hoping to be able to squeeze in durng my lunch break tomorrow. Hoping to get in with the Indy that the previous owner recommended with minimal cost, if any. I will try to pick his brain with the new found info and try to get a quarters worth of advice for a nickel. We'll see... Ty again!

 

Wrong reply

 

Guus,
Even though you edited it as wrong reply, your reply has some relevancy to my situation as I received the email with the original info in it.

It is low all around and I have measured the top of the wheel arches to the top of the tires on all four corners. Bare in mind that about 12 hours ago, I ran the compressor manually for 90 seconds. The front two tires had about 1 1/2" and the rear had about 3/4". The tires are not "sitting" on the tires, but I am guessing that they're on the bump stops, if not close to them. I'm taken pics of all four corners, but the reflection from the measuring tape kind of washes out the actual tire space from being seen, but as I've listed what the measurements are, you can get the point. Can anyone, with a properly functioning compressor, get some fresh measurements or know where I can locate the actual measurements I am referring to or their equivalent?

I do not have the message, "car too low" on the dash, and that had me wondering, "should it be there?".

We've covered the compressors no need to go through it again as I'm sure that horse, or at least the testing I can think of, is long dead. lol

Even though your input was removed, I still found value in it and I thank you for that.

The pics are in the following order 1 is LF, 2 is LR, 3 is RR, 4 is RF

 

So... It's come to this...

Confirmation Code: X********X
Date and Time: 06/23/2014 08:30 AM
Advisor: YARA K
Vehicle: 2004 JAGUAR XJ
Requested Arrangement: Loaner vehicle

Dear JASON,

Thank you for taking the time to schedule your appointment in advance. Your service appointment for 06/23/2014 08:30 AM has been created.

The following services have been selected for this appointment:

Maintenance Services:
Winner's World-Class Courtesy Vehicle Inspection [Jaguar]

Repair Services:
Other Diagnosis

Note: Repair times and costs vary based upon the nature of the repair, parts availability, your warranty status, and other factors. Once your vehicle is in the shop, we will diagnose your problem and contact you as soon as we can to provide details and specific time and cost estimate. Diagnostic and/or repair fees may apply if work to be performed is not covered under warranty.

$140 an hour with an estimated three hour initial allotment anticipated. If it's less time, they'll get less... it it's more than three hours, then I will have to reconsider whether they can adequately track an electrical break if I've done most of the leg work already being that they are "experts"... Not hacking on them (yet), just sayin'

 

Hi Jason,

It's your decision, but given your DIY abilities, you may want to make it clear to the shop that you only want them to scan and read all stored codes. You may choose to do the actual diagnostic work yourself (such as tracking an "electrical break.").

My two cents.

Speaking of electrical breaks, have you confirmed that there is 12V on the terminal in the relay socket that I identified in a previous post? If there is no 12V at that point, then you know the problem is upstream. There have been a couple of reports on the this forum recently of broken wires or bus connections inside the front power distribution fuse box, so if you do not have 12V on that relay socket terminal, that would be the next thing on my list to check. But having the codes read will help isolate the problem so you can focus your diagnostic efforts accordingly.

Cheers,

Don

 

I intend to explain that to them as the receptionist wouldn't allow me to discuss this further with a tech at the time. I have not checked that as of yet as I ran out of light last night as I waited a bit when i got home as the temp hit 105. With no shade on my driveway except under the hood (bonnet). I needed to let the engine cool and, in general, needed a break to clear my head in the hopes of coming up with fresh ideas. With that being said, 5PM can't get here soon enough again so I can make those checks and unbolt the box from the chassis and test under it as well. I can cancel the appt if needed, but wanted to get it scheduled in the event I did need them and I didn't want to have to wait extra days... Thanks again for the ideas and I'll surely post the results when I get them done.

I'm hoping it'll make SOME difference with the techs when I provide a CD with the pics, videos, and write-ups of what I've already checked and what the results were...

I made an edit just now with the relay info you listed earlier with a screen-clip of the schematic you were referring to. This is in the hopes that this thread may help someone else someday who is able to read through my long-winded replies to get to this point...