Hi folks, just had my recond DG 250 trans refitted and it leaks like a sieve. Probably not unusual. Will tolerate while doing other things.
Meantime the reverse light is on when in drive and off in reverse. Have disconnected bulb. Changed the car to -ve earth earlier, Would that be the reason? Not sure where that switch is? Also anti creep switch, is that on the side of the trans? And can start in any gear selector position. Don’t think that’s right. Is there a switch? Where is that switch connected?
Any help be much appreciated.

 

Leaks: Same thing happened to me. I've pretty much given up on the idea of parking my Mark IX on anything but the street or over a drip tray. The engine weeps too even after a full rebuild and upgraded rear main seal. Sigh.

Reverse light: You say it's on in Drive. Is it also on in Park and Neutral? I doubt it would have anything to do with the earth being positive or negative. There's an in-gear start inhibitor switch too; guessing both switches are on the linkages and not the tranny itself, but not sure. Given you can start in any gear, I wonder if they got the wiring mixed up, or if the switches just need adjustment -- or both?

Anti-creep switch solenoid is controlled by two switches: 1) a pressure switch coming off the tranny itself; this tells the solenoid when the tail shaft has stopped spinning, and thus the car is at rest; and 2) a switch on the throttle linkages at the carbs, which deactivates the solenoid once you start depressing the throttle.

Presuming it's the same as the MkIX (and I expect it is), here's the wiring diagram:

 

By the way, aside from the pressure switch on the DG250 for the anti-creep, I'm pretty sure there's an electrical connection for the intermediate speed hold function (activated by the dash switch). If memory serves, those are the only electrical connections on that tranny. I'm pretty sure the switches for start inhibit & backup light are on the selector linkage.

Are you actually trying to hook up the anti-creep? I think most of them are disconnected except perhaps for show-cars.

 

I drove MK7s as my daily car for 15years and have a soft spot for the MK7/8/9.
I did not have automatics in the two Mk7s I owned however I have extensive experience in MK1 and MK2 restorations with automatic transmissions and the manufacturing timeline for these spanned the larger MK7/8/9

Jaguar used a rotary switch driven by a linkage off the automatic gear selector.
It drove both the starting inhibitor switch and the reverse light switch depending on the position arm of the switch. Actually it should be considered as two separate switches in the one housing.
In every Mk1 and MK2 workshop manual I have ever seen (and I have seen a few) the wiring diagram and associated terminals are wrong. This is a well-known problem in the MK1/2 community.
The symptoms you are describing are very much the same as this and I suggest somebody has mis-wired the switch.

Hope this is of some use.
Cheers

 

Please ignore my previous post on this subject as I was wrong.

I have been giving a friend some advice on a MK7 automatic and today had a good look at the electrics involved in the start inhibitor and reverse light switch system.
There are two switches associated with end of the selector column in the engine bay which are activated by cams off the automatic gear selector.
In this right-hand drive car, the switch on the left-hand side closest to the motor is the inhibitor switch.
The switch on the right-hand side is the reverse light switch.
If you are dealing with a left-hand drive car, I would suggest the one closest to the motor is the reverse light and the one closest to the fender is the inhibitor switch.