Trunk/boot lamps

(Greg) #1

So I’ve determined my antenna is blowing my 15amp fuse instantly, so have it disconnected for now.
Now that I have my two trunk lights working, I notice that I cannot turn them off. This button in the corner of the trunk is I assume what controls them when the lid is closed. Pushing the button does nothing, so I assumed a bad switch.
But when I disconnected it, the light will stay on whether the circuit is open or closed.
Not sure what to check next…

(Paul M. Novak) #2

Yes, that switch is supposed to turn on your trunk lights when the trunk is opened and turn them off when the trunk is closed. It is surprising that the trunk lights are on with that switch disconnected. I suspect that the prior owners, or their shops, might have done some creative wiring. If I were you I would remove the trim panels and see if the wiring matches what is shown in the XJ-S ROM wiring diagrams or the S57 Electrical Guide.


(Douglas) #3

My car has some crazy wiring in the trunk lights circuit. That switch is even missing!! I cannot for the life of me figure out what was wrong or what caused a PO to remove that switch.

(Paul M. Novak) #4

My guess is that your car had a battery drain problem due to the trunk lights (seems to be a common cause of battery drain issues) so instead of fixing the switch or buying a new one a prior owner just removed it.


(Douglas) #5

That could well be. The trunk lights dont currently work although the bulbs are good. Seems like the whole circuit is just disabled even. Same for both the passive seatbelts though I think the motors are burnt out independent of a probable leak on the battery they once had.

(scrimbo) #6

???is this switch a hot wire switch or a ground wire switch…it might be a ground switch because of gas tank proximity…I never checked mine…but fuel gauges were usually on the ground side in many cars??? don’t know for sure…but if it is then you have a ground in your lights that is on all the time…do you see what I mean.

(Paul M. Novak) #7

It sounds like you (with a 1989 V12 coupe) and Greg (with a 1988 V12 coupe) need to work together and solve common problems with your cars.


(Greg) #8

Ha, I solved it, Gregma error. I removed all that when putting in fuel tank. Looks like after putting in fuel tank, I hooked it up wrong and bypassed the switch! It is not super obvious how to hook up the wires, but now it’s working.
Regarding lights not working, have you checked the 15amp fuse? Like I said, my antenna keeps blowing the fuse, which is on same circuit as trunk lights.

(Douglas) #9

Agreed. We seem to have gotten our cars at about the same time and are working on very similar projects over last fewmonths! I think Greg has more time and car expertise than me but I’m appreciating his reports and learning as I go down a similar path!

(Paul M. Novak) #10

Yes, according to the Jaguar S57 Electrical Guide for my wife’s 1990 XJ-S convertible the Trunk Light Switch is on the ground side of the circuit and both trunk lights connect to it via a double bullet connector. The Trunk Lights are powered by fuse #3 (15A) and Brown/Purple wires that also power the radio antenna. When the trunk is raised the switch closes and the ground is completed turning on the trunk lights.


(Greg) #11

Now that I have the button switch hooked back up, my trunk lights aren’t working either. So maybe your switch is bad too? I’ve taken mine apart, and can’t figure out how it could complete the circuit, perhaps a part within has broken out. Not sure how to fix this, or replace it?

Hella 6ZF003549001 looks like it will work. Simply solder wires to switch. eBay uk for about $12 w/ shipping.

(Paul M. Novak) #12

That door/trunk switch, Jaguar part number DAC4777, is common part between the Series III XJ6s/XJ12s and the XJ-S. They are no longer available from Jaguar. I have a box of good spare used ones in my garage from my three Series III XJ6 parts cars.

The common failure mode appears to be hardened grease inside that prevents electrical contact. I have had good luck fixing these switches in my Jaguars when they first start to get lazy by disassembling the switch, removing the hardened grease, cleaning and coating the contact surfaces with dielectric grease and reassembling them. Of course if someone else already disassembled your switch and removed some of the internal components then it probably won’t work the way it should.

If you are interested in a good used switch send me a PM. I am sure we can work something out.


(Wayne Canter) #13

Google that part # SNG and Moss motors both offer it new.

Moss says NA , SNG says not in stock but can be ordered

(Greg) #14

I already ordered from eBay UK. Can’t beat $12 new.
Only diff I see are the wires aren’t included. If you look at original oem switch, it says Hella on it.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #15

On my '83, the metal of my trunk lid landed on that switch. I looked at a later model and noticed that it had a little pad of some sort on the underside of the trunk lid to contact that switch. I went home and added a little plastic disc with some trim mounting tape. Not only does it just seem nicer, it also more securely presses the button.

(Greg) #16

I saw in the archives someone mentioned that. I’ll do the same once I get my new switch via the UK. I’m also going to update all those old fashioned glass bulbs with LED. Will be brighter too.

(equiprx) #17

I’ll need to check my parts bin, but I think I have one or two of those lights with on/off switches.
They might have been made for a different car.
I haven’t seen them for years so I’ll need to dig.

(Douglas) #18

Sure! Thanks–maybe we can finally get that box together.

(Paul M. Novak) #19

I have a bunch of good used working switches that I removed from my three Series III XJ6 parts cars. The same basic switch for the XJ-S boot lid was used on all four doors and the trunk lid on the XJ6. If anyone needs one just send me a PM.


(Carl Hutchins, Jr. ) #20

I messed with the one on the left “A” pillar on my car. Remove, clean and replace. No, still worked at times and at times not. Repeated. Ah!!!. erred in the assembly. Fixed. Not so fast. Same issue.

Then touched the plunger sideways. Lights came on. Just plumb wore out. Too much sideways slop

Now, it does nothing. OK, I can mount and dismount in the dark… Lighting not all that bright, anyway…

So, Paul, you might want to test those and see if they all work, or like mine, just worn to far.

I failed to come up with a way to shim the plunger and/or the bore…