I did my best at documenting the wiring before I yanked it all out and replaced every wire that went over the engine. Looks like I slipped up on recording what wires go to the kickdown switch though...

I have one wire that comes up from the area of the transmission (right under the heater control valve) that has no where to go, and I'm thinking this *might* be to the kickdown in the transmission. Since I have no means of getting the car into the air to physically trace the wire, what options do I have to see if my hunch is right?

Secondly, does the other side of the kickdown switch get +12 volts? So when the switch is made the 12 volts through the switch activates the solenoid in the tranny?

Thanks!

John
1987 XJ-S V12, 62,000 miles

 

Was just looking at mine last night. Going from memory (which is dangerous) they are both green, possibly green/brown and green/yellow?

Will take a look tomorrow.

Cheers,

- Will

 

Pretty close :-)

Green and green/white according to my diagrams

Cheers
DD

 

Right !


Cheers
DD

 

All right, thanks!

John

 

Guys, well, I got a chance this weekend to actually work on the kickdown switch issue, and I'm not having much luck. Here is what I've run into...

I now know which wire goes to the solenoid in the tranny. If I put 12 volts on it, I can hear the solenoid activate, which tells me it's likely the right wire (considering where the sound of the "click" is, easier to hear under the car and about where the transmission is), and the other side of the solenoid is grounded, which is in agreement with the crappy wiring diagram I have.

The problem is with the other wire. This green wire has power on it when the ignition is on, but it doesn't care what gear the shift lever is in, it always has 12 volts on it. From reading Kirby's book it seems that the switch that is at the front of the gear selector lever should be in this circuit also, to prevent kickdown when the care is not in drive.

To start somewhere, I put a meter on the switch. I was surprised to see that it is closed, i.e. conducts power, in P, N, and R. Once I shift into Drive, it opens the circuit. This switch has two wires, one is black, the other is yellow with a spiraling purple stripe. As far as I can trace this wiring, it maintains this color scheme, but I see no yellow/purple wire in the engine compartment at all.

Making matters worse is my nearly illegible wiring diagram. I can see the solenoid and the kickdown switch, I don't see any other switch in the line.

So...my questions...

Mine is a 1987. Does anyone know if Jaguar changed the wiring so that maybe earlier (or later) models used the switch in the gear selector to inhibit the kickdown when the car wasn't in drive? I can't say I'm worried about it, since I can't think of any reason I would floor it in any gear other than drive.

Can anyone point me to a web resource that has a legible wiring diagram of a 1987 US coupe?

Oh...the photo shows the microswitch just behind the vertical silver bar that holds it in place. There is another one next to it that looks like it might activate the back-up lights.

Thanks,
John
1987 XJ-S V12, 62,000 miles

 

Right. That's supply voltage to the switch




FWIW, my '88 did not have any sort of kickdown inhibit switch





Yellow/purple wire goes to the *cruise control* inhibit switch....which allows cruise control operation only in "D".






And I don't think you will!






Not that I'm aware of. Others will chime in





Lots of good diagrams on the Captain Jaguar webpage


Cheers
DD

 

The relay with the internal diode is the "main" relay.

The socket for the "main" relay has brown, white, black, and pink/black wires.

The socket for the fuel pump relay has brown, pink/black, orange, and brown/slate wires

Cheers
DD

 

Ok...well, I think I'll just hook it up and forget about any inhibit switch. I'll just have to remember not to stomp on it in reverse...

Thanks!

John

 

JCR

"Making matters worse is my nearly illegible wiring diagram. I can see the solenoid and the kickdown switch, I don't see any other switch in the line."

AFAIK the kickdown switch has nothing at all to do with the capstan microswitches, at least in the UK market specs. The actuual kickdown switch is a microswitch on the solid part of the capstan end of the throttle cable. This triggers the solenoid. The relevant microswitch being activated by a 'bump' on the solid-looking end of the throttle cable, just before the cable end bracket. This mechanism gums up pretty easily, so may need freeing off.



Some owners have fixed a kickdown microswitch to the capstan to replace the standard setup, but this is not factory AFAIK.

Also, AFAIK the gearbox does not do anything if the kickdown solenoid is activated in reverse, which means you are at WOT, so a bit unlikely. It does work in 2nd gear though, and why not, it will certainly get your attention when it does!

Apologies if you knew all this already

Greg

 

I think that one of the gearlever microswitches is the starter inhibit, preventing the starter operating except in neutral and park. (The reversing lights switch is a cylindrical device mounted at rightangles to the quadrant, with a sprung loaded actuating bit poking out of the cylinder towards the lever. It is 'off' until the selector is in the reverse position, when the spring device is allowed to extend a bit further out and make the circuit.)

The other microswitch, according to the Great Palm, if I understand that part of the book correctly, is to inhibit the cruise control from working unless the selector is in Drive.

Greg