Just going to link it and let you guys describe it to me. Not sure whether those are wires or some kind of tube. That's an HVAC line over the top of it. That black stuff looks melted all down the back of the engine and onto the bell housing.

 

No idea what your market calls it

BUT

Down here, its "sticky mastic".

Used by A/C guys to shield the area from engine heat. Basically a bitumas gooey stuff that sticks to anything and usually stays where its moulded into.

Never seen it drooping like that.

Too much solvent based degreaser sprayed on it, will eventually dissolve it, so maybe that is the culprtit.

 

Yup. that is it. messy, huh???

Posting working, again!!!

Carl

 

What's the part with the brass tubes/wires/whatever snaking around it?

Jess

 

A/C "TX valve", as we call it.

I have heard some weird names for it, but that's what I call it.

Memory:

Expansion valve.
Tonnage valve.

All to do with correct operation of the A/C, and YES, the R12 and 134a have a different size orifice, oops.

 

Commonly called "Dum Dum" in the deep south. On the other hand the car seems to have some climate control issues witnessed by the shut of valve installed in the heater line.

 

Oh, you don't know the half of it.

We just this month got the AC to blow cold air into the cabin (A/C condenser failure). The HVAC controls can only turn on the A/C and adjust fan speed. Adjusting temperature does nothing -- it blows full cold all the time -- so trying to run the heater in the winter is futile. I pretty much just park it a couple of weeks before Christmas and don't drive it again until March.

The vents are stuck in defrost mode.

You can sometimes hear servos work, sometimes not. Even when they work, no difference. I've changed the A/C amplifier twice. No improvement. All the fuses are good.

I'm on the verge of coughing up $1200 or so to have some kind of aftermarket HVAC unit installed.

Jess

 

Lost another better post!!!

Add an on/off switch to the compressor clutch. Off in winter will keep out cold and allow warm!!

I added a manual valve to the hose that did not have the vacuum controlled heater hose.
Each closed. No hot coolant in the heater matrix. Run fans in defrost mode. Power vent in mild weather quite pleasant.

My old Jeep has an CAC off switch. Other cars as well !!!

Carlj.

 

?????
What the h... is going on.

I'm off JF for a time at least...
PITA

Carl

 

that is the expansion valve for the a/c system and its capillary tube which should be in a spiral.

the wires are not factory or normal. Nothing else should be there.

the black tar sticky material is insulation for the expansion valve. It can be pulled off.

 

Item #1 here:

https://www.jaguarclassicparts.com/u...ing-components

As mentioned, it's the expansion valve. In your case I can almost promise it's been replaced, evidenced by the extra long capillary tube wadded up in a messy way.

The exp valve used by Jaguar is virtually generic; the same as used a umpteen millions of other cars....except for the length of the capillary tube. Originally, Jaguar (and all the others) used valves with a specific-length capillary tube. However, parts suppliers sell replacements valves with an extra-long tube to accommodate a huge variety of applications with a single part number. The excess tubing looks like hell ....it's impossible to make it actually look nice....but the valves work OK. As Jose said, the original had the (much shorter) capillary tube nicely coiled.

The insulating material "shouldn't" melt down and get all gloppy like that. "Shouldn't", that is, if you can find and buy the original stuff. All the stuff I've tried in recent years melts down. I suspect, but can't confirm, that the original material contained something nasty and thus everyone is selling a not-very-good...but safer... substitute.

Cheers
​​​​​​​DD

 

Jess,
You might have a bad sensor in the system, which will render all your hard work and expense Worthless. Before you throw in the towel, try these tests, courtesy of Gary at Jag-Aire.com:
All test done on Female side of the plug:
TEMPERATURE SELECTOR TEST:
Disconnect the AMP harness and check the resistance between the Blue and White wires while moving the selector through its full range.
It should vary between around 0 and 10K ohms.

AMBIENT AIR SENSOR TEST:
Check resistance between the Blue and Brown wires.
This depends on the ambient temperature of the testing environment. Set the Mode control on AUTO.
For ambient temperature of approximately:
60F, reading should be 16K ohms more or less
70F, reading should be 13K ohms more or less
75F, reading should be 11K ohms more or less
80F, reading should be 10K ohms more or less
85F, reading should be 2.5K ohms more or less

If this sensor, located in the ambient air intake above the driver's knees, is open, your system will be in Full COLD mode all the time.

EDIT: You can simply disconnect your compressor clutch. I have done that, not on Nix, but it was a Very effective way to not have cold air coming through the system.

Nix's AC clutch wire is Green, yours might be a different color.
/edit.
(';')

 

Wowee !!!

Again, I am impressed by the precise post..


Carl.

 

LnrB,

Thanks for the info; one thing I need to make sure everyone knows is that the heater will not come on under any circumstances. The temp wheel occasionally seems to be doing something when you turn it (meaning, activating servos in the system), but most of the time does nothing. However, even in the cases where you can hear servos whirring in the background, there is no change to air temp.

With the compressor hooked up, all mode settings blast the coldest air possible. Sometimes I can select between low, mid and high fan speeds; other times I get only defrost mode. But the air temp is always the same, cold as can be.

With the compressor disconnected in the winter, I still get cold air through the system, it's just ambient air and not cooled air. At no time, ever, does hot water circulate through the system. The hot water shutoff valve you see above was put in back when we thought hot water was mixing in during hot summer months, but it turned out to be an issue with the condenser.

If this car has a fresh/recirculating mode, it is also broken. Only fresh air comes in through the cabin.

Also, even when the fan can be selected to low/mid/high, I still get air through the defroster vents. We were able to determine earlier this year that there is no control over the defroster vent flap happening.

I don't think I have an "issue"; I think I have multiple "issues" occurring simultaneously. You might even call it total system failure. What I do know is I'm done with it. It's just too much of a headache and I get frustrated. I've had two shops look at it. It confounded both of them, too. One told me not to bring the car back.

Jess

P.S.: My 89 XJS also has it's own issues, including being stuck in bi-level mode with hot air being sent to the face vents and cold air to the foot vents rather than the other way around. I've owned four Jags with Delanair systems and none of the four worked properly. They make Lucas look like NASA.

 

Fault tracing on the Delanair systems can be very aggravating, yes. And, yes, a stack-up of different faults is very possible. On one Series III I threw in the towel and converted it to manual control

Sometimes a very slow, methodical checking of electrical connections and vacuum hoses will yield results. I fixed a couple of wonky systems by simply cleaning all the electrical connections. Also, for a 'no heat' situation, check to see that the heater core isn't clogged. Not unusual. I've had to un-clog the cores on two of my Jags

Earlier you mentioned fitting an aftermarket system for $1200. Worth looking into but I have some doubts that $1200 is a realistic number if paying a shop for labor at today's rates

Cheers
DD

 

I'd be interested to know how you did that. Like, really really interested.

I may have just given the parts quote for that aftermarket system, I can't remember. It may have been closer to $2k installed.

Jess

 

in my experience the Red Auxiliary Fan Relay located at the top left of the radiator support, next to the windshield washer bottle, can cause the interior fans Relay and the Servo to malfunction.

it appears to me there are 2 different Red Relays, and their inside wiring is different in later cars. I am not sure of this, but I suspect it.

This Red Relay can cause the SLOW / AUTO / FAST MODES to stop working, causing the system to default to DEFROST MODE.

in my case, replacing the existing Red Relay with one I got from a salvage car brought the system back to life after I had spent days trying to figure out why the MODE switch was not responding.

 

I did it with a 3-position tggle switch and a couple of relays to drive the servo forward or backward, eliminated 'auto' temperature regulation

Nowadays there is a much easier choice to do the same thing, plug-n-play

https://www.jag-aire.com/copy-of-ja-16-details-1

Cheers
DD

 

Just ordered one. And I might get them to rebuild my servo (or buy one from them) if this doesn't do the trick.

Jess