Found out today the compressor had failed (front seal went kablooie) on my 87 XJ6. In addition to replacing the compressor, dryer and expansion valve, the Delanair system driving the whole thing has been a subject of discussion here for about a year.

Essentially, I live in an area where I can't get the Delanair system fixed. No mechanics will take the work. I can no longer do large-scale projects due to health factors. So something has to budge, or I'm stuck with driving a car that basically is stuck in defrost mode at wide-open cool. No heat, no ability to change vents.

I did, however, find a shop that does restoration and resto-mod work on mid-century American cars, with a focus on building hot rods. They have agreed to consider pulling the dash in this car and gutting the Delanair system in favor of an aftermarket A/C unit commonly used to add HVAC to cars that never had it. This is not a system positioned under the dash with a couple of vents blowing out a la an old J.C. Whitney catalog; this system has its own dash vents and/or the ability to tie into existing dash plumbing.

We're looking at about $1,000 for parts, give or take, plus whatever labor charge there is to do the work. According to the shop, all functions of the HVAC system (heat, AC, defrost) will work after the fix, and as a bonus, they can even place rotary controls in the space where the factory rotary controls go. They're not entirely sure the function labels will still match up (probably won't, for that matter) but at least no one will be able to tell just by looking at the controls that the Delanair system is gone.

I'm strongly leaning toward this option given the brick wall I've hit trying to fix the Delanair unit. The only shop within five hours of me told me it could run as much as $5,000 to fix the Delanair system, they wouldn't guarantee they could even do it, but they were going to charge me either way. I paid $3,800 for the entire car; I'm not paying $5,000 to fix the HVAC if an aftermarket system will do the job.

I'll keep you guys updated on the process if I choose to go through with it. If it works, I'll be putting an identical system in my XJS. If anyone has tried this method and would like to offer feedback on their experience, please let me know.

Jess

 

I ended up retaining the S1 Jaguar system (much simpler than your Delanair system used in the later cars). But, I spend a lot of time planning on using a Vintage Air system (there are other good brand choices to select from). I do use their electronic heater servo (gets rid of the Jaguar vacuum controlled water valve).

They will work in your car (or any car) but fitting them in the limited Jag space usually means giving up part of the glove box. I did not care about trying to retain the Jaguar controls but it ended up working perfectly - even kept the same knobs.

I had a '74 SII that I finally got the Delanair AC system working correctly but hated the climate control portion.. AC switching on and off to heat to maintain the temperature is crazy.

If you search this Forum and the other JagForum, there are articles about his switch over and the pitfalls in finding the space for stuff. You have the advantage of having your expansion valve in the engine compartment already.

Putting on a later AC compressor and modern condenser is easy to do. Fitting the evaporator and heating system under the dash and hooking it up as much as possible to your existing vent system is another matter. The controls are the last thing and I would not worry about any change in the "looks".

Any modern AC system will work better than your current system...

 

What you're suggesting sounds feasible but has *anyone* tried *anything* to get your Delanair system working?

They are a PITA at time but some of the repairs are actually simple. I'd hate to think of changing the entire system when all that was needed was an amplifier, or a vacuum hose repaired, or a fuse replaced.

If armed with some specific notes and instructions is there *anyone* who would be willing to take an hour and at least check out a few fundamentals?

Cheers
DD

 

I'm getting a flat "no" all the way around. Some of what you suggested, I did myself: Fuse checks, swapped out the amplifier. There may be a vacuum issue but it's high up under the dash and I can't get to it. That's what all the local shops want to avoid doing -- taking out the dash.

Even if a vacuum line is off, it doesn't explain the electrical problems with the Delanair unit I have. It's acting like an A/C amp is bad (no servo sounds, getting stuck in defrost mode, won't change temperature) but I swapped out my amp with a known good amplifier from another car and the symptoms didn't change a bit.

I live in rural SW Alabama, so my "local" shops (all 1.5-2 hours away) are Mobile, Ala.; Montgomery, Ala.; and Pensacola, Fla. I ended up talking to four shops across those three cities; three turned me down outright and the fourth gave me that ridiculously high quote, probably to scare me off (and it worked). The hot rod shop is actually just up the street from me and I'm familiar with their work; they've been in business as long as I've been alive and they turn out some great cars. He's willing to tear down the dash but he has no familiarity with the Jag A/C system and wants to have Option B ready to go in case he can't fix it.

Jess

 

Ive swapped a complete syatem from a 96 xjs into a 76 xj6c because i wanted the block 134a expansion valve and the xjs box is plastic and weighs much less. It all fit with very minor modifications.

I know both systems inside out backwards and forwards. Neither are beyond a skilled mechanics grasp. But due to expense of a new a/c amplifier and relictance of your local mechanics to learn it may be your only viable alternative unless you get creative.

I dont see how one could fit an aftermarket ac unit with out some major cutting of the center dash support and deletion of the glove box.

If you were here in the north east i have the parts and know how to fix it...i cant be the only one...perhaps there is someone on here closer to you to lend a hand.

The system your have is quite simple. The amplifier takes basically 4 inputs and adjusts 1 motor control accoringly.

Input1. Cabin air temp located in the dash pad

Input2. Incoming air temp, sensor located in the passeger side blower.

Input 3. Dash pot...or the temp setting dial

Input4. On, off defrost.

The three sensors are wired in series and if any 1 of them fail then the system is non operational and will default to defrost mode. They all can be easily tested with a digital volt meter. The free one i got at harbor freight works fine enough.

The most common failures are with one of the three inputs or the amp itself.

Perhaps you could find a local xj6 owner with a working system and ask if you could swap in your a\c amp to test it that way too.

 

icsamerica,

Thanks, I'm not sure I knew previously those sensors were wired in series.

I've already done the A/C amp swap with a known good amp, and nothing changed at all. Looks like it's probably one of those sensors.

I wish there was a way to simply take the computer out of the equation, make it all manually controlled without having to switch complete systems. Automatic A/C is such an unnecessary item in a car.

Jess

 

There is...just wire the one force motor there is with a momentary DPDT switch.

DC Motor Reversing Switch

 

I did that once when I was stuck with a Delaniar that refuse to cooperate. It's just a matter of tapping into the red and blue wires at the servo. Worked well.

One big caution, tho: when using a manual switch you can't let the servo camshaft over-rotate. If you do, things start breaking. Ask me how I know.

Cheers
DD