I am posting this here in hopes that someone else who has installed Jag seats from a more recent vintage can help with this:

I am installing XJ40 Daimler seats in my car. I think they are 1990 vintage.
I am trying to determine how to wire the lamps in the back of the headrests over the picnic tables As you can see in the photo, there are three terminals. The small terminal also has a diode. There is no on/off switch. The headrest has a black/pink wire that I am sure is ground. The large terminal has a brown/white wire and the small terminal has a red/light green wire.

I assume that one of the wires connects to the courtesy lights circuit so when the door is open the light comes on?

Note the rotary dial on the right. It operates a “shade” that dims the light. I am not sure about this but when the shade is rotated all the way open it must break the ground contact because the light goes out - so I guess it does have an on/off switch of sorts.

Any ideas about the connections for the brown/white and the red/light green wires in the MK2?

Lin

 

Set up a little bench test with the rear interior lamp, the B/C pillar lamp and the headrest lamp. Got everything working and discovered a few things.

My B/C pillar lamps, which are new from SNG Barratt, have an on/off slide switch unlike the originals. Any way, as a result of my test I discovered that the on/off switch on the B/C lamp also turns on the rear lamp and the headrest lamp when the central gauge panel interior lamp switch is in the off position. Nice, I guess, that a passenger in the rear seat can turn on all the courtesy lamps with a simple switch at the B/C pillar. Unlike the original B/C pillar lights, these new ones have three wires - a black ground wire, a brown wire for constant power, and a brown/white wire to the door switch. I wired the headrest light the same as the B/C pillar light.

I also discovered that the headrest lamp works just like the other lamps EXCEPT that when all lamps are off, you can rotate the “dial” rotary switch and turn on just the headrest lamp by itself. The other lights do not come on.

With the door closed, the central gauge panel interior light toggle switch turns on the B/C pillar lamp, the rear interior lamp and the headrest lamp.

The problem with the new B/C pillar lamp and with the headrest lamp is that if turned on and left on the battery will drain. While it is not likely that one would leave on four interior lights without noticing, it would be very easy to leave on a headrest lamp. Hmmm. Will have to work on that.

Lin

 

No idea, but I appreciate reading about how you are working through the process of figuring it out. I agree with you, I would try and wire it so that they turned out when the car is off.

 

After thinking about it overnight, I am just not happy with the arrangement I tested last evening. I just don’t like that the lamps could kill the battery if left on. Those little rotary switches are just too tempting for a grandchild to play with. I can see one or both being left in the operable position, so…. Thank you John Stenaik!

I conclude that they really don’t add much as an addition to the four interior courtesy lamps. Therefore, I am inclined to take them off that circuit and to instead wire them to the exterior lights. When the exterior lights are on the rotary switch on the lamps can turn the lamps off, but if one wanted to use them the switch could be used to turn them on. Seems unlikely that one would want to use these lights at a time when the exterior lights would not be on.

What do you think? This is entirely too much deliberation over something that is likely to rarely be used, if ever!

Lin