Hi,


Has anyone experience of retro fitting cruise control to a XJS 3.6 Automatic ?


Is it possible to take the parts from a 4.0 XJS automatic and get them to work with the 3.6 ?


I'm asking as I have a member on my Cabriolet and Convertibles website attempting to undertake this to improve drivability of his Cabriolet.


Thanks in advance for some helpful advice,


Laurence
xjs-soft-tops.com

 

Silly me, I thought cruise control was standard issue on every XJS. I guess not?

I don't know the answer but I would look towards retrofitting with parts from a similar vintage car. By the time 4.0 cars came along I think cruise control was more deeply integrated into the electrical architecture of the car. Older models, much less so....which would make a retro-fit easier. A careful study of wiring diagrams would be a good place to start, IMO.

Cheers
DD

 

Why not.


Probably more complex now in one respect, but simpler in another.


1. I am with Doug as to a transplant from a car that has CC. If the donor car was ever offered with CC, the harness connections may exist. Merely just left open or possibly taped off. Jaguar and other makers did that.


2. Way back in the early 80's I added an after market CC to my base model 79 IHC Scout II. Whether fancier Scout II's or travelers offered it as an option is unknown.
My truck had no traces of one. A carb'd 304, so no computer aboard at all. Actually not complex at all. It used a magnet on the drive haft and a pickup on he chassis adjacent to it. That is where it got a speed sense. The on/off resume control clamped on to the steering post, just under the wheel. A simple box to interpret included.
And a metal bellows ala a small brake boost canister and a chain to the pedal linkage.
A source of vacuum and it worked a charm.


Later, I added a trip computer from the same maker. It used the same speed sensor
for it's speed source. Also worked nicely.


I'm doing VW Passat diagnostics and fix pricing.... Got 9 codes and researched them and related parts to fix via Rock Auto. Most not too bad. But, if it is one or both the cats, oh,oh...... Most of their offerings not CA compliant.


She did mention moving to Texas, it is my daughter's VW. Way back, she loved her Beetles. Did that lead to the Passat oh me....


Carl


Carl

 

I don't know if it was ever an option on the pre-1987 3.6 auto Cabriolet's, though I've come across it on a 1995 4.0 litre auto XJS Coupe. Which is what made me wonder if someone had done it already - save reinventing the wheel (again) :-)
Thanks,
Laurence
xjs-soft-tops.com

 

I am in the process of fitting GM electronic cruise control to my XJS. The module is cheap and fully self contained. But it has required me to re-wire my OEM switches.

There are other options like universal cruise control which would be easier as they come in a kit.

 

At one time Jaguar made a kit to retrofit cruise to X300's, maybe try and get one of those? Part number was JLM11830. It contained the vacuum pump, bellows, ECU, brake switch, wiring and a few other things I can't remember now.

 

Hi Warren,


I'd be interested in a few more details about the GM electronic cruise control you mention and to hear some details of the progress/issues you're facing as you fit it - please.


Laurence

 

I haven't quite finished. The last thing I need to do is cut the inhibit switch ground wire and connect it to a 12V supply. The inhibit switch prevents the CC from operating in any gear but D. The Jag inhibit switch is normally open and closed by a bump on a cam on the gear selector, I need it work the other way around SO I need to either buy a different switch or make a new cam.

Your car being a I6 you could make up a bracket to fit the CC cable to the throttle butterfly. I used the OEM Jaguar setup on the throttle pedal.

Here is a link to a write up I have started

Jaguar XJS Restoration : Jaguar XJS cruise control


The circuit is not quite finished I will update it with all the pin connections to the GM module.
.

 

BTW this is the module I used, I got the cable and loom with connector.

AC Delco Cruise Control Module New Tahoe Full Size Truck 25315559 SA code GM GMC | eBay

 

Thank you for your advice and suggestions

The member has decided to buy a kit and have it fitted by his local Jagaur garage rather than try fitting parts from a donor car

Laurence
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