JustBadly

Start with the basics, check the diff oil level. It takes about 750ml of fluid and is simple to suction out and refill, not a bad idea since original 19yr old fluid will be in there. I use Smith & Allen FS 75w-140.

Only SDD/IDS can access immobiliser faults. Then you can remove the battery sounder and strike it off the dealer options. A fault signal from the battery sounder will trigger the main alarm. Diagnostics will tell you if a module is playing up, all in all recommended. Until then you are doing as much as you can.

Not as scary as it sounds, a Dedicated Ground Return is a negative cable from the alternator that runs back to the battery. Here I have bolted a tag to the alternator housing with the cable lug riveted. Cable is pure copper 8awg, and I used 5 meters. From the tag to behind the FR wheel liner then along the RH rocker cover, then behind the RR wheel liner above the exhaust to a convenient blind grommet into the boot. This is delivering a better charge and it is not surprising since the negative to the battery runs thru 3 meters of mild steel chassis after the engine. The DRG is also better for canbus due to lower signal interference.

I have these and put them in 5 years ago now! Recommended. https://www.ebay.co.uk/itm/165076815757

I think this is what you want. https://www.ebay.co.uk/itm/276758430601

The upper panel has a chip right next to the on/off button. Given time the soldered pins will fail due to board flex, causing this. Remove air-con controller and resolder chip that should do it.

Lower the window by 11". Remove the door card and sticky foam, cut thru the flexible glue. Loosen the two window clamp bolts and remove the glass, always use a suction cup to hold the glass. Remove the speaker box then disconnect the connectors from the door lock and window motor - access the window connector via the port in the door. Unbolt and remove the window slider frame. I have removed the window motor and gearbox but it is not strictly needed, using T25 remove the DC motor and worm drive. Clean the shaft and apply a mid to heavy grease. The light oil used by Jaguar dries and there is metal contact, greatly slowing the DC motor. With that done replace, paying attention to the brush contacts. Re assembly is a reverse of the procedure. With the glass now in keep the window bolts loose and close the window fully, now tighten the glass clamps. Result: one rejuvenated window motor.

If the console is removed and the drop down pocket accessed, the spring can be biased to closing the hatch. It means that when it is 'opened' it only drops slightly and the clip can keep it shut whereas normally it cannot.

The intake flap gaskets are prone to leaking and drip oil goo onto the exhaust downpipe causing smoke on startup. They are accessed at the back of the inlet manifold casting. Gaskets are available from eBay, don't get the electrical connectors mixed up. This advice is for the V6 petrol.

It wouldn't hurt to introduce some lubricant into the vacuum device since there are several springs in there. A spray oil (no silicone) for example, there has to have been a grease or otherwise used during assembly and by this time it will have dried out. Galling, or cold welding as it is sometimes referred to, is a form of severe adhesive wear between two metal surfaces.

The rechargable battery inside the alarm box fails, then the alarm sounds the time. A garage will simply disconnect it. I think I will look at mine and see to replacing the batteries, but probably only when it starts to play up

What type of EPB - Twin wheel mount or single cable actuator?

The place it is situated couldn't be worse for maintenance, if it faults it's a towaway followed by considerable cost. Not to mention the garage has to gather all parts before taking the job on so you lose your car for a month. It really is the elephant in the room for the S Type. Doing this means the actuator is protected from spray, freezing temperature, dust etc. Everything is within reach for servicing. Don't get me wrong this method of EPB is very good since the brake is cable actuated and that lowers unsprung mass but my EPB has not been moved since new and it showed. I had difficulty pulling the EPB cable and all the bolts were a rusted lump. All told this cost about £40 and the original actuator has gone back in yet some clown on eBay wants £1250 for a new S Type parkbrake. Need I say more?

Here I present my conversion removing the parkbrake from it's location above the differential to the spare wheel tub. The diff has to be dropped a few inches with a special tool T10179 needed for the rear bolts. Given space the parkbrake eases out. The actuator was quite rusted and I had to grind every bolt down. However internally it was all ok with new Allens fitted for reassembly. I chose to extend the loom from the parkbrake and feed it to the original plug under the car, the wires to the parkbrake module are very thin. Making a loom rather than intercepting those wires was the easiest option. The parkbrake bolted to the side of the tub with the cable running out to the original route and being reconnected to the cables as normal. The way the cable actuator operates means that for it to be fitted internally there is about one place for it to go. I wanted to do this for a while and although it did not cost a great amount it was a hard days work I don't mind saying.

Pull the ddr module and resolder the chips. With the vibration of driving and door function it can cause pin solder cracks. My car was not responding to the key fob. I bought another ddr module but reworked the original. Now I have 2 working ddr modules. This is the first thing I will do with electrical faults.